talos-obmc-linux/drivers/pci, branch dev-5.0

PCI: pciehp: Assign ctrl->slot_ctrl before writing it to hardware

2019-04-05T20:34:50+00:00

[ Upstream commit 25bd879ec16ad3b83a5b1c3f16faa55e696bfccb ] Shameerali reported that running v4.20-rc1 as QEMU guest, the PCIe hotplug port times out during boot: pciehp 0000:00:01.0:pcie004: Timeout on hotplug command 0x03f1 (issued 1016 msec ago) pciehp 0000:00:01.0:pcie004: Timeout on hotplug command 0x03f1 (issued 1024 msec ago) pciehp 0000:00:01.0:pcie004: Failed to check link status pciehp 0000:00:01.0:pcie004: Timeout on hotplug command 0x02f1 (issued 2520 msec ago) The issue was bisected down to commit 720d6a671a6e ("PCI: pciehp: Do not handle events if interrupts are masked") and was further analyzed by the reporter to be caused by the fact that pciehp first updates the hardware and only then cache the ctrl->slot_ctrl in pcie_do_write_cmd(). If the interrupt happens before we cache the value, pciehp_isr() reads value 0 and decides that the interrupt was not meant for it causing the above timeout to trigger. Fix by moving ctrl->slot_ctrl assignment to happen before it is written to the hardware. Fixes: 720d6a671a6e ("PCI: pciehp: Do not handle events if interrupts are masked") Link: https://lore.kernel.org/linux-pci/5FC3163CFD30C246ABAA99954A238FA8387DD344@FRAEML521-MBX.china.huawei.com Reported-by: Shameerali Kolothum Thodi Signed-off-by: Mika Westerberg Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin

PCI/PME: Fix hotplug/sysfs remove deadlock in pcie_pme_remove()

2019-04-05T20:34:26+00:00

[ Upstream commit 95c80bc6952b6a5badc7b702d23e5bf14d251e7c ] Dongdong reported a deadlock triggered by a hotplug event during a sysfs "remove" operation: pciehp 0000:00:0c.0:pcie004: Slot(0-1): Link Up # echo 1 > 0000:00:0c.0/remove PME and hotplug share an MSI/MSI-X vector. The sysfs "remove" side is: remove_store pci_stop_and_remove_bus_device_locked pci_lock_rescan_remove pci_stop_and_remove_bus_device ... pcie_pme_remove pcie_pme_suspend synchronize_irq # wait for hotplug IRQ handler pci_unlock_rescan_remove The hotplug side is: pciehp_ist pciehp_handle_presence_or_link_change pciehp_configure_device pci_lock_rescan_remove # wait for pci_unlock_rescan_remove() INFO: task bash:10913 blocked for more than 120 seconds. # ps -ax |grep D PID TTY STAT TIME COMMAND 10913 ttyAMA0 Ds+ 0:00 -bash 14022 ? D 0:00 [irq/745-pciehp] # cat /proc/14022/stack __switch_to+0x94/0xd8 pci_lock_rescan_remove+0x20/0x28 pciehp_configure_device+0x30/0x140 pciehp_handle_presence_or_link_change+0x324/0x458 pciehp_ist+0x1dc/0x1e0 # cat /proc/10913/stack __switch_to+0x94/0xd8 synchronize_irq+0x8c/0xc0 pcie_pme_suspend+0xa4/0x118 pcie_pme_remove+0x20/0x40 pcie_port_remove_service+0x3c/0x58 ... pcie_port_device_remove+0x2c/0x48 pcie_portdrv_remove+0x68/0x78 pci_device_remove+0x48/0x120 ... pci_stop_bus_device+0x84/0xc0 pci_stop_and_remove_bus_device_locked+0x24/0x40 remove_store+0xa4/0xb8 dev_attr_store+0x44/0x60 sysfs_kf_write+0x58/0x80 It is incorrect to call pcie_pme_suspend() from pcie_pme_remove() for two reasons. First, pcie_pme_suspend() calls synchronize_irq(), which will wait for the native hotplug interrupt handler as well as for the PME one, because they share one IRQ (as per the spec). That may deadlock if hotplug is signaled while pcie_pme_remove() is running and the latter calls pci_lock_rescan_remove() before the former. Second, if pcie_pme_suspend() figures out that wakeup needs to be enabled for the port, it will return without disabling the interrupt as expected by pcie_pme_remove() which was overlooked by commit c7b5a4e6e8fb ("PCI / PM: Fix native PME handling during system suspend/resume"). To fix that, rework pcie_pme_remove() to disable the PME interrupt, clear its status and prevent the PME worker function from re-enabling it before calling free_irq() on it, which should be sufficient. Fixes: c7b5a4e6e8fb ("PCI / PM: Fix native PME handling during system suspend/resume") Link: https://lore.kernel.org/linux-pci/c7697e7c-e1af-13e4-8491-0a3996e6ab5d@huawei.com Reported-by: Dongdong Liu Signed-off-by: Rafael J. Wysocki [bhelgaas: add URL and deadlock details from Dongdong] Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin

PCI: mediatek: Fix memory mapped IO range size computation

2019-04-05T20:34:25+00:00

[ Upstream commit c61df57343bf05743f8abbb31eec9a6f05820dd1 ] Mediatek's HW assigns a MMIO address range (typically starts from 0x20000000 to 0x2fffffff for both mt2712 and mt7622) for PCI usage. This MMIO address space represents the address space that can be allocated to PCI devices through Base Address Registers. Even though the full MMIO address range is available to be allocated, it should be enabled by the PCIE_AHB_TRANS_BASE register in the host controller and the size that is enabled is determined by AHB2PCIE_SIZE bits in this register. Owing to a bug in the MMIO window size computation, current code does not enable the full size of the available MMIO address range in the PCI host controller; if the PCI devices BARs requested size exceeds the size enabled through the PCIE_AHB_TRANS_BASE register the requests targeting the disabled address address space will be blocked by the root complex causing a system error. Existing code has never run into a system error in production because even half of the enabled MMIO range (128MB) is big enough for typical devices BAR requests (4MB) but the full MMIO address range should be enabled regardless. Fix the MMIO window size computation by using resource_size(mem) instead of mem->end - mem->start. Since the MMIO window size for both MT2712 and MT7622 is 0x10000000, this change will update the parameter passed to fls() from 0xfffffff to 0x10000000 and calculate the whole memory mapped IO range size correctly. Detected through coccinelle semantic patch (and related warning): scripts/coccinelle/api/resource_size.cocci: pcie-mediatek.c:720:13-16: WARNING: Suspicious code. resource_size is maybe missing with mem Signed-off-by: Honghui Zhang [lorenzo.pieralisi@arm.com: rewrote the commit log] Signed-off-by: Lorenzo Pieralisi Signed-off-by: Sasha Levin

PCI: pci-bridge-emul: Extend pci_bridge_emul_init() with flags

2019-03-23T19:11:27+00:00

commit 33776d059630e5045ea9ccf756c74de8f9cc86de upstream. Depending on the capabilities of the PCI controller/platform, the PCI-to-PCI bridge emulation behavior might need to be different. For example, on platforms that use the pci-mvebu code, we currently don't support prefetchable memory BARs, so the corresponding fields in the PCI-to-PCI bridge configuration space should be read-only. To implement this, extend pci_bridge_emul_init() to take a "flags" argument, with currently one flag supported: PCI_BRIDGE_EMUL_NO_PREFETCHABLE_BAR that will make the prefetchable memory base and limit registers read-only. The pci-mvebu and pci-aardvark drivers are updated accordingly. Fixes: 1f08673eef123 ("PCI: mvebu: Convert to PCI emulated bridge config space") Reported-by: Luís Mendes Reported-by: Leigh Brown Tested-by: Leigh Brown Tested-by: Luis Mendes Signed-off-by: Thomas Petazzoni Signed-off-by: Lorenzo Pieralisi Cc: stable@vger.kernel.org Cc: Luís Mendes Cc: Leigh Brown Signed-off-by: Greg Kroah-Hartman

PCI: pci-bridge-emul: Create per-bridge copy of register behavior

2019-03-23T19:11:27+00:00

commit 59f81c35e0df840f7112cb296dde48df84a67c79 upstream. The behavior of the different registers of the PCI-to-PCI bridge is currently encoded in two global arrays, shared by all instances of PCI-to-PCI bridge emulation. However, we will need to tweak the behavior on a per-bridge basis, to accommodate for different capabilities of the platforms where this code is used. In preparation for this, create a per-bridge copy of the register behavior arrays, so that they can later be tweaked on a per-bridge basis. Fixes: 1f08673eef123 ("PCI: mvebu: Convert to PCI emulated bridge config space") Reported-by: Luís Mendes Reported-by: Leigh Brown Tested-by: Leigh Brown Tested-by: Luis Mendes Signed-off-by: Thomas Petazzoni Signed-off-by: Lorenzo Pieralisi Cc: stable@vger.kernel.org Cc: Luís Mendes Cc: Leigh Brown Signed-off-by: Greg Kroah-Hartman

PCI: pciehp: Disable Data Link Layer State Changed event on suspend

2019-03-23T19:11:27+00:00

commit bbe54ea5330d828cc396d451c0e1e5c3f9764c1e upstream. Commit 0e157e528604 ("PCI/PME: Implement runtime PM callbacks") tried to solve an issue where the hierarchy immediately wakes up when it is transitioned into D3cold. However, it turns out to prevent PME propagation on some systems that do not support D3cold. I looked more closely at what might cause the immediate wakeup. It happens when the ACPI power resource of the root port is turned off. The AML code associated with the _OFF() method of the ACPI power resource starts a PCIe L2/L3 Ready transition and waits for it to complete. Right after the L2/L3 Ready transition is started the root port receives a PME from the downstream port. The simplest hierarchy where this happens looks like this: 00:1d.0 PCIe Root Port ^ | v 05:00.0 PCIe switch #1 upstream port 06:01.0 PCIe switch #1 downstream hotplug port ^ | v 08:00.0 PCIe switch #2 upstream port It seems that the PCIe link between the two switches, before PME_Turn_Off/PME_TO_Ack is complete for the whole hierarchy, goes inactive and triggers PME towards the root port bringing it back to D0. The L2/L3 Ready sequence is described in PCIe r4.0 spec sections 5.2 and 5.3.3 but unfortunately they do not state what happens if DLLSCE is enabled during the sequence. Disabling Data Link Layer State Changed event (DLLSCE) seems to prevent the issue and still allows the downstream hotplug port to notice when a device is plugged/unplugged. Link: https://bugzilla.kernel.org/show_bug.cgi?id=202593 Fixes: 0e157e528604 ("PCI/PME: Implement runtime PM callbacks") Signed-off-by: Mika Westerberg Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki CC: stable@vger.kernel.org # v4.20+ Signed-off-by: Greg Kroah-Hartman

PCI: dwc: skip MSI init if MSIs have been explicitly disabled

2019-03-23T19:11:27+00:00

commit 3afc8299f39a27b60e1519a28e18878ce878e7dd upstream. Since 7c5925afbc58 (PCI: dwc: Move MSI IRQs allocation to IRQ domains hierarchical API) the MSI init claims one of the controller IRQs as a chained IRQ line for the MSI controller. On some designs, like the i.MX6, this line is shared with a PCIe legacy IRQ. When the line is claimed for the MSI domain, any device trying to use this legacy IRQs will fail to request this IRQ line. As MSI and legacy IRQs are already mutually exclusive on the DWC core, as the core won't forward any legacy IRQs once any MSI has been enabled, users wishing to use legacy IRQs already need to explictly disable MSI support (usually via the pci=nomsi kernel commandline option). To avoid any issues with MSI conflicting with legacy IRQs, just skip all of the DWC MSI initalization, including the IRQ line claim, when MSI is disabled. Fixes: 7c5925afbc58 ("PCI: dwc: Move MSI IRQs allocation to IRQ domains hierarchical API") Tested-by: Tim Harvey Signed-off-by: Lucas Stach Signed-off-by: Lorenzo Pieralisi Acked-by: Gustavo Pimentel Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

PCI: qcom: Don't deassert reset GPIO during probe

2019-03-23T19:11:27+00:00

commit 02b485e31d98265189b91f3e69c43df2ed50610c upstream. Acquiring the reset GPIO low means that reset is being deasserted, this is followed almost immediately with qcom_pcie_host_init() asserting it, initializing it and then finally deasserting it again, for the link to come up. Some PCIe devices requires a minimum time between the initial deassert and subsequent reset cycles. In a platform that boots with the reset GPIO asserted this requirement is being violated by this deassert/assert pulse. Acquire the reset GPIO high to prevent this situation by matching the state to the subsequent asserted state. Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver") Signed-off-by: Bjorn Andersson [lorenzo.pieralisi@arm.com: updated commit log] Signed-off-by: Lorenzo Pieralisi Acked-by: Stanimir Varbanov Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

PCI/DPC: Fix print AER status in DPC event handling

2019-03-23T19:11:27+00:00

commit 9f08a5d896ce43380314c34ed3f264c8e6075b80 upstream. Previously dpc_handler() called aer_get_device_error_info() without initializing info->severity, so aer_get_device_error_info() relied on uninitialized data. Add dpc_get_aer_uncorrect_severity() to read the port's AER status, mask, and severity registers and set info->severity. Also, clear the port's AER fatal error status bits. Fixes: 8aefa9b0d910 ("PCI/DPC: Print AER status in DPC event handling") Signed-off-by: Dongdong Liu [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas Reviewed-by: Keith Busch Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Greg Kroah-Hartman

PCI/ASPM: Use LTR if already enabled by platform

2019-03-23T19:11:27+00:00

commit 10ecc818ea7319b5d0d2b4e1aa6a77323e776f76 upstream. RussianNeuroMancer reported that the Intel 7265 wifi on a Dell Venue 11 Pro 7140 table stopped working after wakeup from suspend and bisected the problem to 9ab105deb60f ("PCI/ASPM: Disable ASPM L1.2 Substate if we don't have LTR"). David Ward reported the same problem on a Dell Latitude 7350. After af8bb9f89838 ("PCI/ACPI: Request LTR control from platform before using it"), we don't enable LTR unless the platform has granted LTR control to us. In addition, we don't notice if the platform had already enabled LTR itself. After 9ab105deb60f ("PCI/ASPM: Disable ASPM L1.2 Substate if we don't have LTR"), we avoid using LTR if we don't think the path to the device has LTR enabled. The combination means that if the platform itself enables LTR but declines to give the OS control over LTR, we unnecessarily avoided using ASPM L1.2. Link: https://bugzilla.kernel.org/show_bug.cgi?id=201469 Fixes: 9ab105deb60f ("PCI/ASPM: Disable ASPM L1.2 Substate if we don't have LTR") Fixes: af8bb9f89838 ("PCI/ACPI: Request LTR control from platform before using it") Reported-by: RussianNeuroMancer Reported-by: David Ward Signed-off-by: Bjorn Helgaas CC: stable@vger.kernel.org # v4.18+ Signed-off-by: Greg Kroah-Hartman