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* driver core: Postpone DMA tear-down until after devres releaseGeert Uytterhoeven2019-03-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 376991db4b6464e906d699ef07681e2ffa8ab08c upstream. When unbinding the (IOMMU-enabled) R-Car SATA device on Salvator-XS (R-Car H3 ES2.0), in preparation of rebinding against vfio-platform for device pass-through for virtualization:     echo ee300000.sata > /sys/bus/platform/drivers/sata_rcar/unbind the kernel crashes with:     Unable to handle kernel paging request at virtual address ffffffbf029ffffc     Mem abort info:       ESR = 0x96000006       Exception class = DABT (current EL), IL = 32 bits       SET = 0, FnV = 0       EA = 0, S1PTW = 0     Data abort info:       ISV = 0, ISS = 0x00000006       CM = 0, WnR = 0     swapper pgtable: 4k pages, 39-bit VAs, pgdp = 000000007e8c586c     [ffffffbf029ffffc] pgd=000000073bfc6003, pud=000000073bfc6003, pmd=0000000000000000     Internal error: Oops: 96000006 [#1] SMP     Modules linked in:     CPU: 0 PID: 1098 Comm: bash Not tainted 5.0.0-rc5-salvator-x-00452-g37596f884f4318ef #287     Hardware name: Renesas Salvator-X 2nd version board based on r8a7795 ES2.0+ (DT)     pstate: 60400005 (nZCv daif +PAN -UAO)     pc : __free_pages+0x8/0x58     lr : __dma_direct_free_pages+0x50/0x5c     sp : ffffff801268baa0     x29: ffffff801268baa0 x28: 0000000000000000     x27: ffffffc6f9c60bf0 x26: ffffffc6f9c60bf0     x25: ffffffc6f9c60810 x24: 0000000000000000     x23: 00000000fffff000 x22: ffffff8012145000     x21: 0000000000000800 x20: ffffffbf029fffc8     x19: 0000000000000000 x18: ffffffc6f86c42c8     x17: 0000000000000000 x16: 0000000000000070     x15: 0000000000000003 x14: 0000000000000000     x13: ffffff801103d7f8 x12: 0000000000000028     x11: ffffff8011117604 x10: 0000000000009ad8     x9 : ffffff80110126d0 x8 : ffffffc6f7563000     x7 : 6b6b6b6b6b6b6b6b x6 : 0000000000000018     x5 : ffffff8011cf3cc8 x4 : 0000000000004000     x3 : 0000000000080000 x2 : 0000000000000001     x1 : 0000000000000000 x0 : ffffffbf029fffc8     Process bash (pid: 1098, stack limit = 0x00000000c38e3e32)     Call trace:      __free_pages+0x8/0x58      __dma_direct_free_pages+0x50/0x5c      arch_dma_free+0x1c/0x98      dma_direct_free+0x14/0x24      dma_free_attrs+0x9c/0xdc      dmam_release+0x18/0x20      release_nodes+0x25c/0x28c      devres_release_all+0x48/0x4c      device_release_driver_internal+0x184/0x1f0      device_release_driver+0x14/0x1c      unbind_store+0x70/0xb8      drv_attr_store+0x24/0x34      sysfs_kf_write+0x4c/0x64      kernfs_fop_write+0x154/0x1c4      __vfs_write+0x34/0x164      vfs_write+0xb4/0x16c      ksys_write+0x5c/0xbc      __arm64_sys_write+0x14/0x1c      el0_svc_common+0x98/0x114      el0_svc_handler+0x1c/0x24      el0_svc+0x8/0xc     Code: d51b4234 17fffffa a9bf7bfd 910003fd (b9403404)     ---[ end trace 8c564cdd3a1a840f ]--- While I've bisected this to commit e8e683ae9a736407 ("iommu/of: Fix probe-deferral"), and reverting that commit on post-v5.0-rc4 kernels does fix the problem, this turned out to be a red herring. On arm64, arch_teardown_dma_ops() resets dev->dma_ops to NULL. Hence if a driver has used a managed DMA allocation API, the allocated DMA memory will be freed using the direct DMA ops, while it may have been allocated using a custom DMA ops (iommu_dma_ops in this case). Fix this by reversing the order of the calls to devres_release_all() and arch_teardown_dma_ops(). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: stable <stable@vger.kernel.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: Add missing dev->bus->need_parent_lock checksRafael J. Wysocki2018-12-191-2/+2
| | | | | | | | | | | | | __device_release_driver() has to check dev->bus->need_parent_lock before dropping the parent lock and acquiring it again as it may attempt to drop a lock that hasn't been acquired or lock a device that shouldn't be locked and create a lock imbalance. Fixes: 8c97a46af04b (driver core: hold dev's parent lock when needed) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: stable <stable@vger.kernel.org> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: Move async_synchronize_full callAlexander Duyck2018-12-061-3/+3
| | | | | | | | | | | | | | | | | | | | | | Move the async_synchronize_full call out of __device_release_driver and into driver_detach. The idea behind this is that the async_synchronize_full call will only guarantee that any existing async operations are flushed. This doesn't do anything to guarantee that a hotplug event that may occur while we are doing the release of the driver will not be asynchronously scheduled. By moving this into the driver_detach path we can avoid potential deadlocks as we aren't holding the device lock at this point and we should not have the driver we want to flush loaded so the flush will take care of any asynchronous events the driver we are detaching might have scheduled. Fixes: 765230b5f084 ("driver-core: add asynchronous probing support for drivers") Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: fix comments for device_block_probing()Randy Dunlap2018-11-111-2/+2
| | | | | | | | | Correct function name and spelling/typo for device_block_probing() in drivers/base/dd.c. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: Replace simple_strtol by kstrtointMuchun Song2018-11-111-1/+4
| | | | | | | The simple_strtol() function is deprecated, use kstrtoint() instead. Signed-off-by: Muchun Song <smuchun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dma-mapping: remove dma_deconfigureChristoph Hellwig2018-09-081-2/+2
| | | | | | | | This goes through a lot of hooks just to call arch_teardown_dma_ops. Replace it with a direct call instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
* dma-mapping: remove dma_configureChristoph Hellwig2018-09-081-3/+5
| | | | | | | | There is no good reason for this indirection given that the method always exists. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
* Merge 4.18-rc7 into driver-core-nextGreg Kroah-Hartman2018-07-301-8/+0
|\ | | | | | | | | | | We need the driver core changes in here as well for testing. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * driver core: Partially revert "driver core: correct device's shutdown order"Rafael J. Wysocki2018-07-101-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 52cdbdd49853 (driver core: correct device's shutdown order) introduced a regression by breaking device shutdown on some systems. Namely, the devices_kset_move_last() call in really_probe() added by that commit is a mistake as it may cause parents to follow children in the devices_kset list which then causes shutdown to fail. For example, if a device has children before really_probe() is called for it (which is not uncommon), that call will cause it to be reordered after the children in the devices_kset list and the ordering of that list will not reflect the correct device shutdown order any more. Also it causes the devices_kset list to be constantly reordered until all drivers have been probed which is totally pointless overhead in the majority of cases and it only covered an issue with system shutdown, while system-wide suspend/resume potentially had the same issue on the affected platforms (which was not covered). Moreover, the shutdown issue originally addressed by the change in really_probe() made by commit 52cdbdd49853 is not present in 4.18-rc any more, since dra7 started to use the sdhci-omap driver which doesn't disable any regulators during shutdown, so the really_probe() part of commit 52cdbdd49853 can be safely reverted. [The original issue was related to the omap_hsmmc driver used by dra7 previously.] For the above reasons, revert the really_probe() modifications made by commit 52cdbdd49853. The other code changes made by commit 52cdbdd49853 are useful and they need not be reverted. Fixes: 52cdbdd49853 (driver core: correct device's shutdown order) Link: https://lore.kernel.org/lkml/CAFgQCTt7VfqM=UyCnvNFxrSw8Z6cUtAi3HUwR4_xPAc03SgHjQ@mail.gmail.com/ Reported-by: Pingfan Liu <kernelfans@gmail.com> Tested-by: Pingfan Liu <kernelfans@gmail.com> Reviewed-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | driver core: allow stopping deferred probe after initRob Herring2018-07-101-0/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Deferred probe will currently wait forever on dependent devices to probe, but sometimes a driver will never exist. It's also not always critical for a driver to exist. Platforms can rely on default configuration from the bootloader or reset defaults for things such as pinctrl and power domains. This is often the case with initial platform support until various drivers get enabled. There's at least 2 scenarios where deferred probe can render a platform broken. Both involve using a DT which has more devices and dependencies than the kernel supports. The 1st case is a driver may be disabled in the kernel config. The 2nd case is the kernel version may simply not have the dependent driver. This can happen if using a newer DT (provided by firmware perhaps) with a stable kernel version. Deferred probe issues can be difficult to debug especially if the console has dependencies or userspace fails to boot to a shell. There are also cases like IOMMUs where only built-in drivers are supported, so deferring probe after initcalls is not needed. The IOMMU subsystem implemented its own mechanism to handle this using OF_DECLARE linker sections. This commit adds makes ending deferred probe conditional on initcalls being completed or a debug timeout. Subsystems or drivers may opt-in by calling driver_deferred_probe_check_init_done() instead of unconditionally returning -EPROBE_DEFER. They may use additional information from DT or kernel's config to decide whether to continue to defer probe or not. The timeout mechanism is intended for debug purposes and WARNs loudly. The remaining deferred probe pending list will also be dumped after the timeout. Not that this timeout won't work for the console which needs to be enabled before userspace starts. However, if the console's dependencies are resolved, then the kernel log will be printed (as opposed to no output). Cc: Alexander Graf <agraf@suse.de> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | driver core: add a debugfs entry to show deferred devicesJavier Martinez Canillas2018-07-081-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With Device Trees (DT), the dependencies of the devices are defined in the DT, then the drivers parse that information to lookup the needed resources that have as dependencies. Since drivers and devices are registered in a non-deterministic way, it is possible that a device that is a dependency has not been registered yet by the time that is looked up. In this case the driver that requires this dependency cannot probe and has to defer it. So the driver core adds it to a list of deferred devices that is iterated again every time that a new driver is probed successfully. For debugging purposes it may be useful to know what are the devices whose probe function was deferred. Add a debugfs entry showing that information. $ cat /sys/kernel/debug/devices_deferred 48070000.i2c:twl@48:bci musb-hdrc.0.auto omapdrm.0 This information could be obtained partially by enabling debugging, but it means that the kernel log has to be parsed and the probe deferral balanced with the successes. This can be error probe and has to be done in a ad-hoc manner by everyone who needs to debug these kind of issues. Since the information is already known by the kernel, just show it to make it easier to debug. Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | drivers: base: initcall_debug logs for driver probe timesTodd Poynor2018-07-061-28/+22
|/ | | | | | | | | | | | | | | | | | | | Add initcall_debug logs for each driver device probe call, for example: probe of a3800000.ramoops returned 1 after 3007 usecs This replaces the previous code added to report times for deferred probes. It also reports OF platform bus device creates that were formerly lumped together in a single entry for function of_platform_default_populate_init, as well as helping to annotate other initcalls that involve device probing. Remove restriction on printing probe times only during initcalls, since initcall_debug now continues to show driver timing info past the boot phase. Signed-off-by: Todd Poynor <toddpoynor@google.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'pm-4.18-rc1-2' of ↵Linus Torvalds2018-06-131-1/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management updates from Rafael Wysocki: "These revert a recent PM core change that introduced a regression, fix the build when the recently added Kryo cpufreq driver is selected, add support for devices attached to multiple power domains to the generic power domains (genpd) framework, add support for iowait boosting on systens with hardware-managed P-states (HWP) enabled to the intel_pstate driver, modify the behavior of the wakeup_count device attribute in sysfs, fix a few issues and clean up some ugliness, mostly in cpufreq (core and drivers) and in the cpupower utility. Specifics: - Revert a recent PM core change that attempted to fix an issue related to device links, but introduced a regression (Rafael Wysocki) - Fix build when the recently added cpufreq driver for Kryo processors is selected by making it possible to build that driver as a module (Arnd Bergmann) - Fix the long idle detection mechanism in the out-of-band (ondemand and conservative) cpufreq governors (Chen Yu) - Add support for devices in multiple power domains to the generic power domains (genpd) framework (Ulf Hansson) - Add support for iowait boosting on systems with hardware-managed P-states (HWP) enabled to the intel_pstate driver and make it use that feature on systems with Skylake Xeon processors as it is reported to improve performance significantly on those systems (Srinivas Pandruvada) - Fix and update the acpi_cpufreq, ti-cpufreq and imx6q cpufreq drivers (Colin Ian King, Suman Anna, Sébastien Szymanski) - Change the behavior of the wakeup_count device attribute in sysfs to expose the number of events when the device might have aborted system suspend in progress (Ravi Chandra Sadineni) - Fix two minor issues in the cpupower utility (Abhishek Goel, Colin Ian King)" * tag 'pm-4.18-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: Revert "PM / runtime: Fixup reference counting of device link suppliers at probe" cpufreq: imx6q: check speed grades for i.MX6ULL cpufreq: governors: Fix long idle detection logic in load calculation cpufreq: intel_pstate: enable boost for Skylake Xeon PM / wakeup: Export wakeup_count instead of event_count via sysfs PM / Domains: Add dev_pm_domain_attach_by_id() to manage multi PM domains PM / Domains: Add support for multi PM domains per device to genpd PM / Domains: Split genpd_dev_pm_attach() PM / Domains: Don't attach devices in genpd with multi PM domains PM / Domains: dt: Allow power-domain property to be a list of specifiers cpufreq: intel_pstate: New sysfs entry to control HWP boost cpufreq: intel_pstate: HWP boost performance on IO wakeup cpufreq: intel_pstate: Add HWP boost utility and sched util hooks cpufreq: ti-cpufreq: Use devres managed API in probe() cpufreq: ti-cpufreq: Fix an incorrect error return value cpufreq: ACPI: make function acpi_cpufreq_fast_switch() static cpufreq: kryo: allow building as a loadable module cpupower : Fix header name to read idle state name cpupower: fix spelling mistake: "logilename" -> "logfilename"
| * Revert "PM / runtime: Fixup reference counting of device link suppliers at ↵Rafael J. Wysocki2018-06-121-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | probe" Revert commit 1e8378619841 (PM / runtime: Fixup reference counting of device link suppliers at probe), as it has introduced a regression and the condition it was designed to address should be covered by the existing code. Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | Merge tag 'driver-core-4.18-rc1' of ↵Linus Torvalds2018-06-051-4/+4
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the driver core patchset for 4.18-rc1. The large chunk of these are firmware core documentation and api updates. Nothing major there, just better descriptions for others to be able to understand the firmware code better. There's also a user for a new firmware api call. Other than that, there are some minor updates for debugfs, kernfs, and the driver core itself. All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (23 commits) driver core: hold dev's parent lock when needed driver-core: return EINVAL error instead of BUG_ON() driver core: add __printf verification to device_create_groups_vargs mm: memory_hotplug: use put_device() if device_register fail base: core: fix typo 'can by' to 'can be' debugfs: inode: debugfs_create_dir uses mode permission from parent debugfs: Re-use kstrtobool_from_user() Documentation: clarify firmware_class provenance and why we can't rename the module Documentation: remove stale firmware API reference Documentation: fix few typos and clarifications for the firmware loader ath10k: re-enable the firmware fallback mechanism for testmode ath10k: use firmware_request_nowarn() to load firmware firmware: add firmware_request_nowarn() - load firmware without warnings firmware_loader: make firmware_fallback_sysfs() print more useful firmware_loader: move kconfig FW_LOADER entries to its own file firmware_loader: replace ---help--- with help firmware_loader: enhance Kconfig documentation over FW_LOADER firmware_loader: document firmware_sysfs_fallback() firmware: rename fw_sysfs_fallback to firmware_fallback_sysfs() firmware: use () to terminate kernel-doc function names ...
| * driver core: hold dev's parent lock when neededMartin Liu2018-05-311-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SoC have internal I/O buses that can't be proved for devices. The devices on the buses can be accessed directly without additinal configuration required. This type of bus is represented as "simple-bus". In some platforms, we name "soc" with "simple-bus" attribute and many devices are hooked under it described in DT (device tree). In commit bf74ad5bc417 ("Hold the device's parent's lock during probe and remove") to solve USB subsystem lock sequence since USB device's characteristic. Thus "soc" needs to be locked whenever a device and driver's probing happen under "soc" bus. During this period, an async driver tries to probe a device which is under the "soc" bus would be blocked until previous driver finish the probing and release "soc" lock. And the next probing under the "soc" bus need to wait for async finish. Because of that, driver's async probe for init time improvement will be shadowed. Since many devices don't have USB devices' characteristic, they actually don't need parent's lock. Thus, we introduce a lock flag in bus_type struct and driver core would lock the parent lock base on the flag. For USB, we set this flag in usb_bus_type to keep original lock behavior in driver core. Async probe could have more benefit after this patch. Signed-off-by: Martin Liu <liumartin@google.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | PM / runtime: Fixup reference counting of device link suppliers at probeUlf Hansson2018-05-271-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the driver core, before it invokes really_probe() it runtime resumes the suppliers for the device via calling pm_runtime_get_suppliers(), which also increases the runtime PM usage count for each of the available supplier. This makes sense, as to be able to allow the consumer device to be probed by its driver. However, if the driver decides to add a new supplier link during ->probe(), hence updating the list of suppliers, the following call to pm_runtime_put_suppliers(), invoked after really_probe() in the driver core, we get into trouble. More precisely, pm_runtime_put() gets called also for the new supplier(s), which is wrong as the driver core, didn't trigger pm_runtime_get_sync() to be called for it in the first place. In other words, the new supplier may be runtime suspended even in cases when it shouldn't. Fix this behaviour, by runtime resume suppliers according to the same conditions as managed by the runtime PM core, when runtime resume callbacks are being invoked. Additionally, don't try to runtime suspend any of the suppliers after really_probe(), but instead rely on that to happen via the consumer device, when it becomes runtime suspended. Fixes: 21d5c57b3726 (PM / runtime: Use device links) Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | PM / core: fix deferred probe breaking suspend resume orderFeng Kan2018-04-241-3/+1
|/ | | | | | | | | | | | | | | | | | When bridge and its endpoint is enumerated the devices are added to the dpm list. Afterward, the bridge defers probe when IOMMU is not ready. This causes the bridge to be moved to the end of the dpm list when deferred probe kicks in. The order of the dpm list for bridge and endpoint is reversed. Add reordering code to move the bridge and its children and consumers to the end of the pm list so the order for suspend and resume is not altered. The code also move device and its children and consumers to the tail of device_kset list if it is registered. Signed-off-by: Toan Le <toanle@apm.com> Signed-off-by: Feng Kan <fkan@apm.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* drivers: base: remove check for callback in coredump_store()Arend van Spriel2018-03-231-2/+1
| | | | | | | | | The check for the .coredump() callback in coredump_store() is redundant. It is already assured the device driver implements the callback upon creating the coredump sysfs entry. Signed-off-by: Arend van Spriel <aspriel@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers: base: add coredump driver opsArend van Spriel2018-01-231-7/+33
| | | | | | | | | | | This adds the coredump driver operation. When the driver defines it a coredump file is added in the sysfs folder of the device upon driver binding. The file is removed when the driver is unbound. User-space can trigger a coredump for this device by echo'ing to the coredump file. Signed-off-by: Arend van Spriel <aspriel@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: Remove redundant license textGreg Kroah-Hartman2017-12-071-2/+0
| | | | | | | | | | | | | | | | | Now that the SPDX tag is in all driver core files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: add SPDX identifiers to all driver core filesGreg Kroah-Hartman2017-12-071-0/+1
| | | | | | | | | | | | | | | | | | | | | It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the driver core files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: William Breathitt Gray <vilhelm.gray@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'driver-core-4.15-rc1' of ↵Linus Torvalds2017-11-161-4/+12
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the set of driver core / debugfs patches for 4.15-rc1. Not many here, mostly all are debugfs fixes to resolve some long-reported problems with files going away with references to them in userspace. There's also some SPDX cleanups for the debugfs code, as well as a few other minor driver core changes for issues reported by people. All of these have been in linux-next for a week or more with no reported issues" * tag 'driver-core-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: driver core: Fix device link deferred probe debugfs: Remove redundant license text debugfs: add SPDX identifiers to all debugfs files debugfs: defer debugfs_fsdata allocation to first usage debugfs: call debugfs_real_fops() only after debugfs_file_get() debugfs: purge obsolete SRCU based removal protection IB/hfi1: convert to debugfs_file_get() and -put() debugfs: convert to debugfs_file_get() and -put() debugfs: debugfs_real_fops(): drop __must_hold sparse annotation debugfs: implement per-file removal protection debugfs: add support for more elaborate ->d_fsdata driver core: Move device_links_purge() after bus_remove_device() arch_topology: Fix section miss match warning due to free_raw_capacity() driver-core: pr_err() strings should end with newlines
| * driver core: Fix device link deferred probeAdrian Hunter2017-11-081-4/+12
| | | | | | | | | | | | | | | | | | | | A device probe deferred because of a device link is never probed again because it is not added to the deferred_probe_pending_list. Add it, taking care of the race with driver_deferred_probe_trigger(). Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | PM / core: Add NEVER_SKIP and SMART_PREPARE driver flagsRafael J. Wysocki2017-11-061-0/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The motivation for this change is to provide a way to work around a problem with the direct-complete mechanism used for avoiding system suspend/resume handling for devices in runtime suspend. The problem is that some middle layer code (the PCI bus type and the ACPI PM domain in particular) returns positive values from its system suspend ->prepare callbacks regardless of whether the driver's ->prepare returns a positive value or 0, which effectively prevents drivers from being able to control the direct-complete feature. Some drivers need that control, however, and the PCI bus type has grown its own flag to deal with this issue, but since it is not limited to PCI, it is better to address it by adding driver flags at the core level. To that end, add a driver_flags field to struct dev_pm_info for flags that can be set by device drivers at the probe time to inform the PM core and/or bus types, PM domains and so on on the capabilities and/or preferences of device drivers. Also add two static inline helpers for setting that field and testing it against a given set of flags and make the driver core clear it automatically on driver remove and probe failures. Define and document two PM driver flags related to the direct- complete feature: NEVER_SKIP and SMART_PREPARE that can be used, respectively, to indicate to the PM core that the direct-complete mechanism should never be used for the device and to inform the middle layer code (bus types, PM domains etc) that it can only request the PM core to use the direct-complete mechanism for the device (by returning a positive value from its ->prepare callback) if it also has been requested by the driver. While at it, make the core check pm_runtime_suspended() when setting power.direct_complete so that it doesn't need to be checked by ->prepare callbacks. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
* initcall_debug: add deferred probe timesTodd Poynor2017-08-031-1/+27
| | | | | | | | | | | | | | | | initcall_debug attributes all deferred device probe retries for the late_initcall level to function deferred_probe_initcall. Add logs of the individual device probe routines called, to identify which drivers are executing for how long during the initcall path. Deferred probes that occur after initcall processing are not shown. Example log messages added: [ 0.505119] deferred probe my-sound-device @ 6 [ 0.517656] deferred probe my-sound-device returned after 1227 usecs Signed-off-by: Todd Poynor <toddpoynor@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: emit uevents when device is bound to a driverDmitry Torokhov2017-07-221-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | There are certain touch controllers that may come up in either normal (application) or boot mode, depending on whether firmware/configuration is corrupted when they are powered on. In boot mode the kernel does not create input device instance (because it does not necessarily know the characteristics of the input device in question). Another number of controllers does not store firmware in a non-volatile memory, and they similarly need to have firmware loaded before input device instance is created. There are also other types of devices with similar behavior. There is a desire to be able to trigger firmware loading via udev, but it has to happen only when driver is bound to a physical device (i2c or spi). These udev actions can not use ADD events, as those happen too early, so we are introducing BIND and UNBIND events that are emitted at the right moment. Also, many drivers create additional driver-specific device attributes when binding to the device, to provide userspace with additional controls. The new events allow userspace to adjust these driver-specific attributes without worrying that they are not there yet. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* of/acpi: Configure dma operations at probe time for platform/amba/pci bus ↵Sricharan R2017-04-201-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | devices Configuring DMA ops at probe time will allow deferring device probe when the IOMMU isn't available yet. The dma_configure for the device is now called from the generic device_attach callback just before the bus/driver probe is called. This way, configuring the DMA ops for the device would be called at the same place for all bus_types, hence the deferred probing mechanism should work for all buses as well. pci_bus_add_devices (platform/amba)(_device_create/driver_register) | | pci_bus_add_device (device_add/driver_register) | | device_attach device_initial_probe | | __device_attach_driver __device_attach_driver | driver_probe_device | really_probe | dma_configure Similarly on the device/driver_unregister path __device_release_driver is called which inturn calls dma_deconfigure. This patch changes the dma ops configuration to probe time for both OF and ACPI based platform/amba/pci bus devices. Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Bjorn Helgaas <bhelgaas@google.com> (drivers/pci part) Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sricharan R <sricharan@codeaurora.org> Signed-off-by: Joerg Roedel <jroedel@suse.de>
* Revert "driver core: Add deferred_probe attribute to devices in sysfs"Greg Kroah-Hartman2017-01-141-13/+0
| | | | | | | | | | | This reverts commit 6751667a29d6fd64afb9ce30567ad616b68ed789. Rob Herring objected to it, and a replacement for it will be added using debugfs in the future. Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Reported-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'driver-core-4.10-rc1' of ↵Linus Torvalds2016-12-131-13/+66
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here's the new driver core patches for 4.10-rc1. Big thing here is the nice addition of "functional dependencies" to the driver core. The idea has been talked about for a very long time, great job to Rafael for stepping up and implementing it. It's been tested for longer than the 4.9-rc1 date, we held off on merging it earlier in order to feel more comfortable about it. Other than that, it's just a handful of small other patches, some good cleanups to the mess that is the firmware class code, and we have a test driver for the deferred probe logic. All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (30 commits) firmware: Correct handling of fw_state_wait() return value driver core: Silence device links sphinx warning firmware: remove warning at documentation generation time drivers: base: dma-mapping: Fix typo in dmam_alloc_non_coherent comments driver core: test_async: fix up typo found by 0-day firmware: move fw_state_is_done() into UHM section firmware: do not use fw_lock for fw_state protection firmware: drop bit ops in favor of simple state machine firmware: refactor loading status firmware: fix usermode helper fallback loading driver core: firmware_class: convert to use class_groups driver core: devcoredump: convert to use class_groups driver core: class: add class_groups support kernfs: Declare two local data structures static driver-core: fix platform_no_drv_owner.cocci warnings drivers/base/memory.c: Remove unused 'first_page' variable driver core: add CLASS_ATTR_WO() drivers: base: cacheinfo: support DT overrides for cache properties drivers: base: cacheinfo: add pr_fmt logging drivers: base: cacheinfo: fix boot error message when acpi is enabled ...
| * driver core: Add deferred_probe attribute to devices in sysfsBen Hutchings2016-11-101-0/+13
| | | | | | | | | | | | | | | | | | It is sometimes useful to know that a device is on the deferred probe list rather than, say, not having a driver available. Expose this information to user-space. Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * PM / runtime: Use device linksRafael J. Wysocki2016-10-311-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Modify the runtime PM framework to use device links to ensure that supplier devices will not be suspended if any of their consumer devices are active. The idea is to reference count suppliers on the consumer's resume and drop references to them on its suspend. The information on whether or not the supplier has been reference counted by the consumer's (runtime) resume is stored in a new field (rpm_active) in the link object for each link. It may be necessary to clean up those references when the supplier is unbinding and that's why the links whose status is DEVICE_LINK_SUPPLIER_UNBIND are skipped by the runtime suspend and resume code. The above means that if the consumer device is probed in the runtime-active state, the supplier has to be resumed and reference counted by device_link_add() so the code works as expected on its (runtime) suspend. There is a new flag, DEVICE_LINK_RPM_ACTIVE, to tell device_link_add() about that (in which case the caller is responsible for making sure that the consumer really will be runtime-active when runtime PM is enabled for it). The other new link flag, DEVICE_LINK_PM_RUNTIME, tells the core whether or not the link should be used for runtime PM at all. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * driver core: Functional dependencies tracking supportRafael J. Wysocki2016-10-311-5/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, there is a problem with taking functional dependencies between devices into account. What I mean by a "functional dependency" is when the driver of device B needs device A to be functional and (generally) its driver to be present in order to work properly. This has certain consequences for power management (suspend/resume and runtime PM ordering) and shutdown ordering of these devices. In general, it also implies that the driver of A needs to be working for B to be probed successfully and it cannot be unbound from the device before the B's driver. Support for representing those functional dependencies between devices is added here to allow the driver core to track them and act on them in certain cases where applicable. The argument for doing that in the driver core is that there are quite a few distinct use cases involving device dependencies, they are relatively hard to get right in a driver (if one wants to address all of them properly) and it only gets worse if multiplied by the number of drivers potentially needing to do it. Morever, at least one case (asynchronous system suspend/resume) cannot be handled in a single driver at all, because it requires the driver of A to wait for B to suspend (during system suspend) and the driver of B to wait for A to resume (during system resume). For this reason, represent dependencies between devices as "links", with the help of struct device_link objects each containing pointers to the "linked" devices, a list node for each of them, status information, flags, and an RCU head for synchronization. Also add two new list heads, representing the lists of links to the devices that depend on the given one (consumers) and to the devices depended on by it (suppliers), and a "driver presence status" field (needed for figuring out initial states of device links) to struct device. The entire data structure consisting of all of the lists of link objects for all devices is protected by a mutex (for link object addition/removal and for list walks during device driver probing and removal) and by SRCU (for list walking in other case that will be introduced by subsequent change sets). If CONFIG_SRCU is not selected, however, an rwsem is used for protecting the entire data structure. In addition, each link object has an internal status field whose value reflects whether or not drivers are bound to the devices pointed to by the link or probing/removal of their drivers is in progress etc. That field is only modified under the device links mutex, but it may be read outside of it in some cases (introduced by subsequent change sets), so modifications of it are annotated with WRITE_ONCE(). New links are added by calling device_link_add() which takes three arguments: pointers to the devices in question and flags. In particular, if DL_FLAG_STATELESS is set in the flags, the link status is not to be taken into account for this link and the driver core will not manage it. In turn, if DL_FLAG_AUTOREMOVE is set in the flags, the driver core will remove the link automatically when the consumer device driver unbinds from it. One of the actions carried out by device_link_add() is to reorder the lists used for device shutdown and system suspend/resume to put the consumer device along with all of its children and all of its consumers (and so on, recursively) to the ends of those lists in order to ensure the right ordering between all of the supplier and consumer devices. For this reason, it is not possible to create a link between two devices if the would-be supplier device already depends on the would-be consumer device as either a direct descendant of it or a consumer of one of its direct descendants or one of its consumers and so on. There are two types of link objects, persistent and non-persistent. The persistent ones stay around until one of the target devices is deleted, while the non-persistent ones are removed automatically when the consumer driver unbinds from its device (ie. they are assumed to be valid only as long as the consumer device has a driver bound to it). Persistent links are created by default and non-persistent links are created when the DL_FLAG_AUTOREMOVE flag is passed to device_link_add(). Both persistent and non-persistent device links can be deleted with an explicit call to device_link_del(). Links created without the DL_FLAG_STATELESS flag set are managed by the driver core using a simple state machine. There are 5 states each link can be in: DORMANT (unused), AVAILABLE (the supplier driver is present and functional), CONSUMER_PROBE (the consumer driver is probing), ACTIVE (both supplier and consumer drivers are present and functional), and SUPPLIER_UNBIND (the supplier driver is unbinding). The driver core updates the link state automatically depending on what happens to the linked devices and for each link state specific actions are taken in addition to that. For example, if the supplier driver unbinds from its device, the driver core will also unbind the drivers of all of its consumers automatically under the assumption that they cannot function properly without the supplier. Analogously, the driver core will only allow the consumer driver to bind to its device if the supplier driver is present and functional (ie. the link is in the AVAILABLE state). If that's not the case, it will rely on the existing deferred probing mechanism to wait for the supplier driver to become available. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * driver core: Add a wrapper around __device_release_driver()Rafael J. Wysocki2016-10-281-12/+18
| | | | | | | | | | | | | | | | | | | | Add an internal wrapper around __device_release_driver() that will acquire device locks and do the necessary checks before calling it. The next patch will make use of it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | driver core: fix smatch warning on dev->bus checkRob Herring2016-10-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit d42a09802174 (driver core: skip removal test for non-removable drivers) introduced a smatch warning: drivers/base/dd.c:386 really_probe() warn: variable dereferenced before check 'dev->bus' (see line 373) Fix the warning by removing the dev->bus NULL check. dev->bus will never be NULL, so the check was unnecessary. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | driver core: skip removal test for non-removable driversRob Herring2016-10-311-1/+2
|/ | | | | | | | | | | | | | | | Some drivers do not support removal/unbinding. These drivers should have drv->suppress_bind_attrs set to true, so use that to skip the removal test. This doesn't fix anything reported so far, but should prevent some other cases. Some drivers will need fixes to set suppress_bind_attrs to avoid this test. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=177021 Fixes: bea5b158ff0d ("driver core: add test of driver remove calls during probe") Reported-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* device core: Remove deprecated create_singlethread_workqueueBhaktipriya Shridhar2016-09-021-9/+3
| | | | | | | | | | | | | | | | | | | | | | | The workqueue "deferred_wq" queues a single work item &deferred_probe_work and hence doesn't require ordering. It is involved in probing devices and is not being used on a memory reclaim path. Hence, it has been converted to use system_wq. System workqueues have been able to handle high level of concurrency for a long time now and hence it's not required to have a singlethreaded workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue created with create_singlethread_workqueue(), system_wq allows multiple work items to overlap executions even on the same CPU; however, a per-cpu workqueue doesn't have any CPU locality or global ordering guarantee unless the target CPU is explicitly specified and thus the increase of local concurrency shouldn't make any difference. The work item has been flushed in driver_probe_done() to ensure that there are no pending tasks while disconnecting the driver. Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: add test of driver remove calls during probeRob Herring2016-08-311-0/+21
| | | | | | | | | | | | | In recent discussions on ksummit-discuss[1], it was suggested to do a sequence of probe, remove, probe for testing driver remove paths. This adds a kconfig option for said test. [1] https://lists.linuxfoundation.org/pipermail/ksummit-discuss/2016-August/003459.html Suggested-by: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()Tomeu Vizoso2016-02-161-2/+22
| | | | | | | | | | | | | | | | | | | Allow implementations of the match() callback in struct bus_type to return errors and if it's -EPROBE_DEFER then queue the device for deferred probing. This is useful to buses such as AMBA in which devices are registered before their matching information can be retrieved from the HW (typically because a clock driver hasn't probed yet). [changed if-else code structure, adjusted documentation to match the code, extended comments] Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* driver core: Avoid NULL pointer dereferences in device_is_bound()Rafael J. Wysocki2016-01-121-1/+1
| | | | | | | | | | | If device_is_bound() is called on a device that's not been registered yet, it will attepmt to dereference dev->p which is NULL, so avoid that by checking dev->p in there against NULL. Fixes: 6b9cb42752da "device core: add device_is_bound()" Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* PM / sleep: Go direct_complete if driver has no callbacksTomeu Vizoso2016-01-081-0/+3
| | | | | | | | | | | | | | If a suitable prepare callback cannot be found for a given device and its driver has no PM callbacks at all, assume that it can go direct to complete when the system goes to sleep. The reason for this is that there's lots of devices in a system that do no PM at all and there's no reason for them to prevent their ancestors to do direct_complete if they can support it. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* device core: add device_is_bound()Tomeu Vizoso2016-01-081-2/+16
| | | | | | | | | | | | | | | Adds a function that tells whether a device is already bound to a driver. This is needed to warn when there is an attempt to change the PM domain of a device that has finished probing already. The reason why we want to enforce that is because in the general case that can cause problems and also that we can simplify code quite a bit if we can always assume that. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* Merge branch 'acpi-soc' into pm-coreRafael J. Wysocki2016-01-081-2/+8
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| * device core: add BUS_NOTIFY_DRIVER_NOT_BOUND notificationAndy Shevchenko2015-12-091-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The users of BUS_NOTIFY_BIND_DRIVER have no chance to do any cleanup in case of a probe failure. In the result there might be problems, such as some resources that had been allocated will continue to be allocated and therefore lead to a resource leak. Introduce a new notification to inform the subscriber that ->probe() failed. Do the same in case of failed device_bind_driver() call. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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| \
*-. \ Merge branches 'pm-sleep' and 'pm-runtime' into pm-coreRafael J. Wysocki2015-12-071-1/+49
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| | * PM / runtime: Re-init runtime PM states at probe error and driver unbindUlf Hansson2015-11-301-0/+2
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two common expectations among several subsystems/drivers that deploys runtime PM support, but which isn't met by the driver core. Expectation 1) At ->probe() the subsystem/driver expects the runtime PM status of the device to be RPM_SUSPENDED, which is the initial status being assigned at device registration. This expectation is especially common among some of those subsystems/ drivers that manages devices with an attached PM domain, as those requires the ->runtime_resume() callback at the PM domain level to be invoked during ->probe(). Moreover these subsystems/drivers entirely relies on runtime PM resources being managed at the PM domain level, thus don't implement their own set of runtime PM callbacks. These are two scenarios that suffers from this unmet expectation. i) A failed ->probe() sequence requests probe deferral: ->probe() ... pm_runtime_enable() pm_runtime_get_sync() ... err: pm_runtime_put() pm_runtime_disable() ... As there are no guarantees that such sequence turns the runtime PM status of the device into RPM_SUSPENDED, the re-trying ->probe() may start with the status in RPM_ACTIVE. In such case the runtime PM core won't invoke the ->runtime_resume() callback because of a pm_runtime_get_sync(), as it considers the device to be already runtime resumed. ii) A driver re-bind sequence: At driver unbind, the subsystem/driver's >remove() callback invokes a sequence of runtime PM APIs, to undo actions during ->probe() and to put the device into low power state. ->remove() ... pm_runtime_put() pm_runtime_disable() ... Similar as in the failing ->probe() case, this sequence don't guarantee the runtime PM status of the device to turn into RPM_SUSPENDED. Trying to re-bind the driver thus causes the same issue as when re-trying ->probe(), in the probe deferral scenario. Expectation 2) Drivers that invokes the pm_runtime_irq_safe() API during ->probe(), triggers the runtime PM core to increase the usage count for the device's parent and permanently make it runtime resumed. The usage count is only dropped at device removal, which also allows it to be runtime suspended again. A re-trying ->probe() repeats the call to pm_runtime_irq_safe() and thus once more triggers the usage count of the device's parent to be increased. This leads to not only an imbalance issue of the usage count of the device's parent, but also to keep it runtime resumed permanently even if ->probe() fails. To address these issues, let's change the policy of the driver core to meet these expectations. More precisely, at ->probe() failures and driver unbind, restore the initial states of runtime PM. Although to still allow subsystem's to control PM for devices that doesn't ->probe() successfully, don't restore the initial states unless runtime PM is disabled. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * PM / sleep: prohibit devices probing during suspend/hibernationStrashko, Grygorii2015-11-301-1/+47
|/ | | | | | | | | | | | | | | | | | | | | It is unsafe [1] if probing of devices will happen during suspend or hibernation and system behavior will be unpredictable in this case. So, let's prohibit device's probing in dpm_prepare() and defer their probing instead. The normal behavior will be restored in dpm_complete(). This patch introduces new DD core APIs: device_block_probing() It will disable probing of devices and defer their probes instead. device_unblock_probing() It will restore normal behavior and trigger re-probing of deferred devices. [1] https://lkml.org/lkml/2015/9/11/554 Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* drivers/pinctrl: Add the concept of an "init" stateDouglas Anderson2015-10-271-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For pinctrl the "default" state is applied to pins before the driver's probe function is called. This is normally a sensible thing to do, but in some cases can cause problems. That's because the pins will change state before the driver is given a chance to program how those pins should behave. As an example you might have a regulator that is controlled by a PWM (output high = high voltage, output low = low voltage). The firmware might leave this pin as driven high. If we allow the driver core to reconfigure this pin as a PWM pin before the PWM's probe function runs then you might end up running at too low of a voltage while we probe. Let's introudce a new "init" state. If this is defined we'll set pinctrl to this state before probe and then "default" after probe (unless the driver explicitly changed states already). An alternative idea that was thought of was to use the pre-existing "sleep" or "idle" states and add a boolean property that we should start in that mode. This was not done because the "init" state is needed for correctness and those other states are only present (and only transitioned in to and out of) when (optional) power management is enabled. Changes in v3: - Moved declarations to pinctrl/devinfo.h - Fixed author/SoB Changes in v2: - Added comment to pinctrl_init_done() as per Linus W. Signed-off-by: Douglas Anderson <dianders@chromium.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Caesar Wang <wxt@rock-chips.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
* Merge tag 'pm+acpi-4.3-rc1' of ↵Linus Torvalds2015-09-011-0/+20
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI updates from Rafael Wysocki: "From the number of commits perspective, the biggest items are ACPICA and cpufreq changes with the latter taking the lead (over 50 commits). On the cpufreq front, there are many cleanups and minor fixes in the core and governors, driver updates etc. We also have a new cpufreq driver for Mediatek MT8173 chips. ACPICA mostly updates its debug infrastructure and adds a number of fixes and cleanups for a good measure. The Operating Performance Points (OPP) framework is updated with new DT bindings and support for them among other things. We have a few updates of the generic power domains framework and a reorganization of the ACPI device enumeration code and bus type operations. And a lot of fixes and cleanups all over. Included is one branch from the MFD tree as it contains some PM-related driver core and ACPI PM changes a few other commits are based on. Specifics: - ACPICA update to upstream revision 20150818 including method tracing extensions to allow more in-depth AML debugging in the kernel and a number of assorted fixes and cleanups (Bob Moore, Lv Zheng, Markus Elfring). - ACPI sysfs code updates and a documentation update related to AML method tracing (Lv Zheng). - ACPI EC driver fix related to serialized evaluations of _Qxx methods and ACPI tools updates allowing the EC userspace tool to be built from the kernel source (Lv Zheng). - ACPI processor driver updates preparing it for future introduction of CPPC support and ACPI PCC mailbox driver updates (Ashwin Chaugule). - ACPI interrupts enumeration fix for a regression related to the handling of IRQ attribute conflicts between MADT and the ACPI namespace (Jiang Liu). - Fixes related to ACPI device PM (Mika Westerberg, Srinidhi Kasagar). - ACPI device registration code reorganization to separate the sysfs-related code and bus type operations from the rest (Rafael J Wysocki). - Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause, Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss). - ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups (Pan Xinhui, Rafael J Wysocki). - cpufreq core cleanups on top of the previous changes allowing it to preseve its sysfs directories over system suspend/resume (Viresh Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior). - cpufreq fixes and cleanups related to governors (Viresh Kumar). - cpufreq updates (core and the cpufreq-dt driver) related to the turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz). - New DT bindings for Operating Performance Points (OPP), support for them in the OPP framework and in the cpufreq-dt driver plus related OPP framework fixes and cleanups (Viresh Kumar). - cpufreq powernv driver updates (Shilpasri G Bhat). - New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen). - Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean). - intel_pstate driver updates including Skylake-S support, support for enabling HW P-states per CPU and an additional vendor bypass list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao). - cpuidle core fixes related to the handling of coupled idle states (Xunlei Pang). - intel_idle driver updates including Skylake Client support and support for freeze-mode-specific idle states (Len Brown). - Driver core updates related to power management (Andy Shevchenko, Rafael J Wysocki). - Generic power domains framework fixes and cleanups (Jon Hunter, Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson). - Device PM QoS framework update to allow the latency tolerance setting to be exposed to user space via sysfs (Mika Westerberg). - devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas). - System sleep support updates (Alan Stern, Len Brown, SungEun Kim). - rockchip-io AVS support updates (Heiko Stuebner). - PM core clocks support fixup (Colin Ian King). - Power capping RAPL driver update including support for Skylake H/S and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi). - Generic device properties framework fixes related to the handling of static (driver-provided) property sets (Andy Shevchenko). - turbostat and cpupower updates (Len Brown, Shilpasri G Bhat, Shreyas B Prabhu)" * tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (180 commits) cpufreq: speedstep-lib: Use monotonic clock cpufreq: powernv: Increase the verbosity of OCC console messages cpufreq: sfi: use kmemdup rather than duplicating its implementation cpufreq: drop !cpufreq_driver check from cpufreq_parse_governor() cpufreq: rename cpufreq_real_policy as cpufreq_user_policy cpufreq: remove redundant 'policy' field from user_policy cpufreq: remove redundant 'governor' field from user_policy cpufreq: update user_policy.* on success cpufreq: use memcpy() to copy policy cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event cpufreq: mediatek: Add MT8173 cpufreq driver dt-bindings: mediatek: Add MT8173 CPU DVFS clock bindings PM / Domains: Fix typo in description of genpd_dev_pm_detach() PM / Domains: Remove unusable governor dummies PM / Domains: Make pm_genpd_init() available to modules PM / domains: Align column headers and data in pm_genpd_summary output powercap / RAPL: disable the 2nd power limit properly tools: cpupower: Fix error when running cpupower monitor PM / OPP: Drop unlikely before IS_ERR(_OR_NULL) PM / OPP: Fix static checker warning (broken 64bit big endian systems) ...
| * Driver core: wakeup the parent device before trying probeRafael J. Wysocki2015-07-281-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the parent is still suspended when driver probe is attempted, the result may be failure. For example, if the parent is a PCI MFD device that has been suspended when we try to probe our device, any register reads will return 0xffffffff. To fix the problem, making sure the parent is always awake before attempting driver probe. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
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