linux-stable.git/drivers/pci, branch v5.4.261

PCI: Prevent xHCI driver from claiming AMD VanGogh USB3 DRD device

2023-11-08T10:23:42+00:00

commit 7e6f3b6d2c352b5fde37ce3fed83bdf6172eebd4 upstream.

The AMD VanGogh SoC contains a DesignWare USB3 Dual-Role Device that can be
operated as either a USB Host or a USB Device, similar to on the AMD Nolan
platform.

be6646bfbaec ("PCI: Prevent xHCI driver from claiming AMD Nolan USB3 DRD
device") added a quirk to let the dwc3 driver claim the Nolan device since
it provides more specific support.

Extend that quirk to include the VanGogh SoC USB3 device.

Link: https://lore.kernel.org/r/20230927202212.2388216-1-vi@endrift.com
Signed-off-by: Vicki Pfau 
[bhelgaas: include be6646bfbaec reference, add stable tag]
Signed-off-by: Bjorn Helgaas 
Cc: stable@vger.kernel.org	# v3.19+
Signed-off-by: Greg Kroah-Hartman

Revert "PCI: qcom: Disable write access to read only registers for IP v2.3.3"

2023-10-10T19:46:42+00:00

This reverts commit 35c95eda7b6d9883d1cc9bb1f89d454baa140ebc which is
commit a33d700e8eea76c62120cb3dbf5e01328f18319a upstream.

It was applied to the incorrect function as the original function the
commit changed is not in this kernel branch.

Reported-by: Ben Hutchings 
Link: https://lore.kernel.org/r/f23affddab4d8b3cc07508f2d8735d88d823821d.camel@decadent.org.uk
Signed-off-by: Greg Kroah-Hartman

Revert "PCI: Mark NVIDIA T4 GPUs to avoid bus reset"

2023-09-23T08:59:55+00:00

commit 5260bd6d36c83c5b269c33baaaf8c78e520908b0 upstream.

This reverts commit d5af729dc2071273f14cbb94abbc60608142fd83.

d5af729dc207 ("PCI: Mark NVIDIA T4 GPUs to avoid bus reset") avoided
Secondary Bus Reset on the T4 because the reset seemed to not work when the
T4 was directly attached to a Root Port.

But NVIDIA thinks the issue is probably related to some issue with the Root
Port, not with the T4.  The T4 provides neither PM nor FLR reset, so
masking bus reset compromises this device for assignment scenarios.

Revert d5af729dc207 as requested by Wu Zongyong.  This will leave SBR
broken in the specific configuration Wu tested, as it was in v6.5, so Wu
will debug that further.

Link: https://lore.kernel.org/r/ZPqMCDWvITlOLHgJ@wuzongyong-alibaba
Link: https://lore.kernel.org/r/20230908201104.GA305023@bhelgaas
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Greg Kroah-Hartman

PCI/ASPM: Use RMW accessors for changing LNKCTL

2023-09-23T08:59:47+00:00

[ Upstream commit e09060b3b6b4661278ff8e1b7b81a37d5ea86eae ]

Don't assume that the device is fully under the control of ASPM and use RMW
capability accessors which do proper locking to avoid losing concurrent
updates to the register values.

If configuration fails in pcie_aspm_configure_common_clock(), the
function attempts to restore the old PCI_EXP_LNKCTL_CCC settings. Store
only the old PCI_EXP_LNKCTL_CCC bit for the relevant devices rather
than the content of the whole LNKCTL registers. It aligns better with
how pcie_lnkctl_clear_and_set() expects its parameter and makes the
code more obvious to understand.

Suggested-by: Lukas Wunner 
Fixes: 2a42d9dba784 ("PCIe: ASPM: Break out of endless loop waiting for PCI config bits to switch")
Fixes: 7d715a6c1ae5 ("PCI: add PCI Express ASPM support")
Link: https://lore.kernel.org/r/20230717120503.15276-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen 
Signed-off-by: Bjorn Helgaas 
Acked-by: "Rafael J. Wysocki" 
Signed-off-by: Sasha Levin

PCI: pciehp: Use RMW accessors for changing LNKCTL

2023-09-23T08:59:47+00:00

[ Upstream commit 5f75f96c61039151c193775d776fde42477eace1 ]

As hotplug is not the only driver touching LNKCTL, use the RMW capability
accessor which handles concurrent changes correctly.

Suggested-by: Lukas Wunner 
Fixes: 7f822999e12a ("PCI: pciehp: Add Disable/enable link functions")
Link: https://lore.kernel.org/r/20230717120503.15276-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen 
Signed-off-by: Bjorn Helgaas 
Acked-by: "Rafael J. Wysocki" 
Signed-off-by: Sasha Levin

PCI: Mark NVIDIA T4 GPUs to avoid bus reset

2023-09-23T08:59:47+00:00

[ Upstream commit d5af729dc2071273f14cbb94abbc60608142fd83 ]

NVIDIA T4 GPUs do not work with SBR. This problem is found when the T4 card
is direct attached to a Root Port only. Avoid bus reset by marking T4 GPUs
PCI_DEV_FLAGS_NO_BUS_RESET.

Fixes: 4c207e7121fa ("PCI: Mark some NVIDIA GPUs to avoid bus reset")
Link: https://lore.kernel.org/r/2dcebea53a6eb9bd212ec6d8974af2e5e0333ef6.1681129861.git.wuzongyong@linux.alibaba.com
Signed-off-by: Wu Zongyong 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Sasha Levin

PCI: acpiphp: Use pci_assign_unassigned_bridge_resources() only for non-root bus

2023-08-30T14:27:26+00:00

commit cc22522fd55e257c86d340ae9aedc122e705a435 upstream.

40613da52b13 ("PCI: acpiphp: Reassign resources on bridge if necessary")
changed acpiphp hotplug to use pci_assign_unassigned_bridge_resources()
which depends on bridge being available, however enable_slot() can be
called without bridge associated:

  1. Legitimate case of hotplug on root bus (widely used in virt world)

  2. A (misbehaving) firmware, that sends ACPI Bus Check notifications to
     non existing root ports (Dell Inspiron 7352/0W6WV0), which end up at
     enable_slot(..., bridge = 0) where bus has no bridge assigned to it.
     acpihp doesn't know that it's a bridge, and bus specific 'PCI
     subsystem' can't augment ACPI context with bridge information since
     the PCI device to get this data from is/was not available.

Issue is easy to reproduce with QEMU's 'pc' machine, which supports PCI
hotplug on hostbridge slots. To reproduce, boot kernel at commit
40613da52b13 in VM started with following CLI (assuming guest root fs is
installed on sda1 partition):

  # qemu-system-x86_64 -M pc -m 1G -enable-kvm -cpu host \
        -monitor stdio -serial file:serial.log           \
        -kernel arch/x86/boot/bzImage                    \
        -append "root=/dev/sda1 console=ttyS0"           \
        guest_disk.img

Once guest OS is fully booted at qemu prompt:

  (qemu) device_add e1000

(check serial.log) it will cause NULL pointer dereference at:

  void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
  {
    struct pci_bus *parent = bridge->subordinate;

  BUG: kernel NULL pointer dereference, address: 0000000000000018

   ? pci_assign_unassigned_bridge_resources+0x1f/0x260
   enable_slot+0x21f/0x3e0
   acpiphp_hotplug_notify+0x13d/0x260
   acpi_device_hotplug+0xbc/0x540
   acpi_hotplug_work_fn+0x15/0x20
   process_one_work+0x1f7/0x370
   worker_thread+0x45/0x3b0

The issue was discovered on Dell Inspiron 7352/0W6WV0 laptop with following
sequence:

  1. Suspend to RAM
  2. Wake up with the same backtrace being observed:
  3. 2nd suspend to RAM attempt makes laptop freeze

Fix it by using __pci_bus_assign_resources() instead of
pci_assign_unassigned_bridge_resources() as we used to do, but only in case
when bus doesn't have a bridge associated (to cover for the case of ACPI
event on hostbridge or non existing root port).

That lets us keep hotplug on root bus working like it used to and at the
same time keeps resource reassignment usable on root ports (and other 1st
level bridges) that was fixed by 40613da52b13.

Fixes: 40613da52b13 ("PCI: acpiphp: Reassign resources on bridge if necessary")
Link: https://lore.kernel.org/r/20230726123518.2361181-2-imammedo@redhat.com
Reported-by: Woody Suwalski 
Tested-by: Woody Suwalski 
Tested-by: Michal Koutný 
Link: https://lore.kernel.org/r/11fc981c-af49-ce64-6b43-3e282728bd1a@gmail.com
Signed-off-by: Igor Mammedov 
Signed-off-by: Bjorn Helgaas 
Acked-by: Rafael J. Wysocki 
Acked-by: Michael S. Tsirkin 
Signed-off-by: Greg Kroah-Hartman

PCI: acpiphp: Reassign resources on bridge if necessary

2023-08-30T14:27:20+00:00

[ Upstream commit 40613da52b13fb21c5566f10b287e0ca8c12c4e9 ]

When using ACPI PCI hotplug, hotplugging a device with large BARs may fail
if bridge windows programmed by firmware are not large enough.

Reproducer:
  $ qemu-kvm -monitor stdio -M q35  -m 4G \
      -global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=on \
      -device id=rp1,pcie-root-port,bus=pcie.0,chassis=4 \
      disk_image

 wait till linux guest boots, then hotplug device:
   (qemu) device_add qxl,bus=rp1

 hotplug on guest side fails with:
   pci 0000:01:00.0: [1b36:0100] type 00 class 0x038000
   pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x03ffffff]
   pci 0000:01:00.0: reg 0x14: [mem 0x00000000-0x03ffffff]
   pci 0000:01:00.0: reg 0x18: [mem 0x00000000-0x00001fff]
   pci 0000:01:00.0: reg 0x1c: [io  0x0000-0x001f]
   pci 0000:01:00.0: BAR 0: no space for [mem size 0x04000000]
   pci 0000:01:00.0: BAR 0: failed to assign [mem size 0x04000000]
   pci 0000:01:00.0: BAR 1: no space for [mem size 0x04000000]
   pci 0000:01:00.0: BAR 1: failed to assign [mem size 0x04000000]
   pci 0000:01:00.0: BAR 2: assigned [mem 0xfe800000-0xfe801fff]
   pci 0000:01:00.0: BAR 3: assigned [io  0x1000-0x101f]
   qxl 0000:01:00.0: enabling device (0000 -> 0003)
   Unable to create vram_mapping
   qxl: probe of 0000:01:00.0 failed with error -12

However when using native PCIe hotplug
  '-global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off'
it works fine, since kernel attempts to reassign unused resources.

Use the same machinery as native PCIe hotplug to (re)assign resources.

Link: https://lore.kernel.org/r/20230424191557.2464760-1-imammedo@redhat.com
Signed-off-by: Igor Mammedov 
Signed-off-by: Bjorn Helgaas 
Acked-by: Michael S. Tsirkin 
Acked-by: Rafael J. Wysocki 
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin

PCI/ASPM: Avoid link retraining race

2023-08-11T09:53:45+00:00

[ Upstream commit e7e39756363ad5bd83ddeae1063193d0f13870fd ]

PCIe r6.0.1, sec 7.5.3.7, recommends setting the link control parameters,
then waiting for the Link Training bit to be clear before setting the
Retrain Link bit.

This avoids a race where the LTSSM may not use the updated parameters if it
is already in the midst of link training because of other normal link
activity.

Wait for the Link Training bit to be clear before toggling the Retrain Link
bit to ensure that the LTSSM uses the updated link control parameters.

[bhelgaas: commit log, return 0 (success)/-ETIMEDOUT instead of bool for
both pcie_wait_for_retrain() and the existing pcie_retrain_link()]
Suggested-by: Lukas Wunner 
Fixes: 7d715a6c1ae5 ("PCI: add PCI Express ASPM support")
Link: https://lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Lukas Wunner 
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin

PCI/ASPM: Factor out pcie_wait_for_retrain()

2023-08-11T09:53:45+00:00

[ Upstream commit 9c7f136433d26592cb4d9cd00b4e15c33d9797c6 ]

Factor pcie_wait_for_retrain() out from pcie_retrain_link().  No functional
change intended.

[bhelgaas: split out from
https: //lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com]
Signed-off-by: Ilpo Järvinen 
Signed-off-by: Bjorn Helgaas 
Stable-dep-of: e7e39756363a ("PCI/ASPM: Avoid link retraining race")
Signed-off-by: Sasha Levin