talos-obmc-linux/drivers/pci, branch v3.12

Revert "ACPI / hotplug / PCI: Avoid doing too much for spurious notifies"

2013-10-30T14:28:52+00:00

Commit 2dc4128 (ACPI / hotplug / PCI: Avoid doing too much for spurious notifies) changed the enable_slot() to check return value of pci_scan_slot() and if it is zero return early from the function. It means that there were no new devices in this particular slot. However, if a device appeared deeper in the hierarchy the code now ignores it causing things like Thunderbolt chaining fail to recognize new devices. The problem with Alex Williamson's machine was solved with commit a47d8c8 (ACPI / hotplug / PCI: Avoid parent bus rescans on spurious device checks) and hence we should be able to restore the original functionality that we always rescan on bus check notification. On a device check notification we still check what acpiphp_rescan_slot() returns and on zero bail out early. Fixes: 2dc41281b1d1 (ACPI / hotplug / PCI: Avoid doing too much for spurious notifies) Signed-off-by: Mika Westerberg Tested-by: Alex Williamson Signed-off-by: Rafael J. Wysocki

ACPI / hotplug / PCI: Drop WARN_ON() from acpiphp_enumerate_slots()

2013-10-11T23:49:48+00:00

The WARN_ON() in acpiphp_enumerate_slots() triggers unnecessarily for devices whose bridges are going to be handled by native PCIe hotplug (pciehp) and the simplest way to prevent that from happening is to drop the WARN_ON(). References: https://bugzilla.kernel.org/show_bug.cgi?id=62831 Reported-by: Steven Rostedt Signed-off-by: Rafael J. Wysocki

ACPI / hotplug / PCI: Fix error code path in acpiphp_enumerate_slots()

2013-10-11T23:47:43+00:00

One of the error code paths in acpiphp_enumerate_slots() is missing a pci_dev_put(bridge->pci_dev) call, so add it. Signed-off-by: Rafael J. Wysocki Acked-by: Bjorn Helgaas

PCI: Workaround missing pci_set_master in pci drivers

2013-09-28T20:25:30+00:00

Ben Herrenschmidt found that commit 928bea964827 ("PCI: Delay enabling bridges until they're needed") breaks PCI in some powerpc environments. The reason is that the PCIe port driver will call pci_enable_device() on the bridge, so the device is enabled, but skips pci_set_master because pcie_port_auto and no acpi on powerpc. Because of that, pci_enable_bridge() later on (called as a result of the child device driver doing pci_enable_device) will see the bridge as already enabled and will not call pci_set_master() on it. Fixed by add checking in pci_enable_bridge, and call pci_set_master if driver skip that. That will make the code more robot and wade off problem for missing pci_set_master in drivers. Reported-by: Benjamin Herrenschmidt Signed-off-by: Yinghai Lu Signed-off-by: Linus Torvalds

PCI / ACPI / PM: Clear pme_poll for devices in D3cold on wakeup

2013-09-19T22:24:43+00:00

Commit 448bd85 (PCI/PM: add PCIe runtime D3cold support) added a piece of code to pci_acpi_wake_dev() causing that function to behave in a special way for devices in D3cold (so that their configuration registers are not accessed before those devices are resumed). However, it didn't take the clearing of the pme_poll flag into account. That has to be done for all devices, even if they are in D3cold, or pci_pme_list_scan() will not know that wakeup has been signaled for the device and will poll its PME Status bit unnecessarily. Fix the problem by moving the clearing of the pme_poll flag in pci_acpi_wake_dev() before the code introduced by commit 448bd85. Reported-and-tested-by: David E. Box Signed-off-by: Rafael J. Wysocki Acked-by: Bjorn Helgaas Cc: 3.6+ # 3.6+

Remove GENERIC_HARDIRQ config option

2013-09-13T13:09:52+00:00

After the last architecture switched to generic hard irqs the config options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code for !CONFIG_GENERIC_HARDIRQS can be removed. Signed-off-by: Martin Schwidefsky

Merge tag 'pm+acpi-fixes-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2013-09-12T18:22:45+00:00

Pull ACPI and power management fixes from Rafael Wysocki: "All of these commits are fixes that have emerged recently and some of them fix bugs introduced during this merge window. Specifics: 1) ACPI-based PCI hotplug (ACPIPHP) fixes related to spurious events After the recent ACPIPHP changes we've seen some interesting breakage on a system that triggers device check notifications during boot for non-existing devices. Although those notifications are really spurious, we should be able to deal with them nevertheless and that shouldn't introduce too much overhead. Four commits to make that work properly. 2) Memory hotplug and hibernation mutual exclusion rework This was maent to be a cleanup, but it happens to fix a classical ABBA deadlock between system suspend/hibernation and ACPI memory hotplug which is possible if they are started roughly at the same time. Three commits rework memory hotplug so that it doesn't acquire pm_mutex and make hibernation use device_hotplug_lock which prevents it from racing with memory hotplug. 3) ACPI Intel LPSS (Low-Power Subsystem) driver crash fix The ACPI LPSS driver crashes during boot on Apple Macbook Air with Haswell that has slightly unusual BIOS configuration in which one of the LPSS device's _CRS method doesn't return all of the information expected by the driver. Fix from Mika Westerberg, for stable. 4) ACPICA fix related to Store->ArgX operation AML interpreter fix for obscure breakage that causes AML to be executed incorrectly on some machines (observed in practice). From Bob Moore. 5) ACPI core fix for PCI ACPI device objects lookup There still are cases in which there is more than one ACPI device object matching a given PCI device and we don't choose the one that the BIOS expects us to choose, so this makes the lookup take more criteria into account in those cases. 6) Fix to prevent cpuidle from crashing in some rare cases If the result of cpuidle_get_driver() is NULL, which can happen on some systems, cpuidle_driver_ref() will crash trying to use that pointer and the Daniel Fu's fix prevents that from happening. 7) cpufreq fixes related to CPU hotplug Stephen Boyd reported a number of concurrency problems with cpufreq related to CPU hotplug which are addressed by a series of fixes from Srivatsa S Bhat and Viresh Kumar. 8) cpufreq fix for time conversion in time_in_state attribute Time conversion carried out by cpufreq when user space attempts to read /sys/devices/system/cpu/cpu*/cpufreq/stats/time_in_state won't work correcty if cputime_t doesn't map directly to jiffies. Fix from Andreas Schwab. 9) Revert of a troublesome cpufreq commit Commit 7c30ed5 (cpufreq: make sure frequency transitions are serialized) was intended to address some known concurrency problems in cpufreq related to the ordering of transitions, but unfortunately it introduced several problems of its own, so I decided to revert it now and address the original problems later in a more robust way. 10) Intel Haswell CPU models for intel_pstate from Nell Hardcastle. 11) cpufreq fixes related to system suspend/resume The recent cpufreq changes that made it preserve CPU sysfs attributes over suspend/resume cycles introduced a possible NULL pointer dereference that caused it to crash during the second attempt to suspend. Three commits from Srivatsa S Bhat fix that problem and a couple of related issues. 12) cpufreq locking fix cpufreq_policy_restore() should acquire the lock for reading, but it acquires it for writing. Fix from Lan Tianyu" * tag 'pm+acpi-fixes-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (25 commits) cpufreq: Acquire the lock in cpufreq_policy_restore() for reading cpufreq: Prevent problems in update_policy_cpu() if last_cpu == new_cpu cpufreq: Restructure if/else block to avoid unintended behavior cpufreq: Fix crash in cpufreq-stats during suspend/resume intel_pstate: Add Haswell CPU models Revert "cpufreq: make sure frequency transitions are serialized" cpufreq: Use signed type for 'ret' variable, to store negative error values cpufreq: Remove temporary fix for race between CPU hotplug and sysfs-writes cpufreq: Synchronize the cpufreq store_*() routines with CPU hotplug cpufreq: Invoke __cpufreq_remove_dev_finish() after releasing cpu_hotplug.lock cpufreq: Split __cpufreq_remove_dev() into two parts cpufreq: Fix wrong time unit conversion cpufreq: serialize calls to __cpufreq_governor() cpufreq: don't allow governor limits to be changed when it is disabled ACPI / bind: Prefer device objects with _STA to those without it ACPI / hotplug / PCI: Avoid parent bus rescans on spurious device checks ACPI / hotplug / PCI: Use _OST to notify firmware about notify status ACPI / hotplug / PCI: Avoid doing too much for spurious notifies ACPICA: Fix for a Store->ArgX when ArgX contains a reference to a field. ACPI / hotplug / PCI: Don't trim devices before scanning the namespace ...

Merge branch 'acpi-pci-hotplug'

2013-09-10T21:15:02+00:00

* acpi-pci-hotplug: ACPI / hotplug / PCI: Avoid parent bus rescans on spurious device checks ACPI / hotplug / PCI: Use _OST to notify firmware about notify status ACPI / hotplug / PCI: Avoid doing too much for spurious notifies ACPI / hotplug / PCI: Don't trim devices before scanning the namespace

ACPI / hotplug / PCI: Avoid parent bus rescans on spurious device checks

2013-09-09T19:41:07+00:00

In the current ACPIPHP notify handler we always go directly for a rescan of the parent bus if we get a device check notification for a device that is not a bridge. However, this obviously is overzealous if nothing really changes, because this way we may rescan the whole PCI hierarchy pretty much in vain. That happens on Alex Williamson's machine whose ACPI tables contain device objects that are supposed to coresspond to PCIe root ports, but those ports aren't physically present (or at least they aren't visible in the PCI config space to us). The BIOS generates multiple device check notifies for those objects during boot and for each of them we go straight for the parent bus rescan, but the parent bus is the root bus in this particular case. In consequence, we rescan the whole PCI bus from the top several times in a row, which is completely unnecessary, increases boot time by 50% (after previous fixes) and generates excess dmesg output from the PCI subsystem. Fix the problem by checking if we can find anything new in the slot corresponding to the device we've got a device check notify for and doing nothig if that's not the case. The spec (ACPI 5.0, Section 5.6.6) appears to mandate this behavior, as it says: Device Check. Used to notify OSPM that the device either appeared or disappeared. If the device has appeared, OSPM will re-enumerate from the parent. If the device has disappeared, OSPM will invalidate the state of the device. OSPM may optimize out re-enumeration. Therefore, according to the spec, we are free to do nothing if nothing changes. References: https://bugzilla.kernel.org/show_bug.cgi?id=60865 Reported-and-tested-by: Alex Williamson Signed-off-by: Rafael J. Wysocki

ACPI / hotplug / PCI: Use _OST to notify firmware about notify status

2013-09-07T01:43:58+00:00

The spec suggests that we should use _OST to notify the platform about the status of notifications it sends us, for example so that it doesn't repeate a notification that has been handled already. This turns out to help reduce the amount of diagnostic output from the ACPIPHP subsystem and speed up boot on at least one system that generates multiple device check notifies for PCIe devices on the root bus during boot. Reported-and-tested-by: Alex Williamson Signed-off-by: Rafael J. Wysocki