** Description changed:
- [SRU] Impact:
- Some AMD APU multi-function devices expose an integrated USB xHCI controller.
- When the system resumes from suspend, the xHCI controller can complete
- pci_pm_resume and start resuming USB devices while the GPU is still in its
- much longer resume path. This race condition leads to USB device resume
- failures with:
- xhci_hcd: xHCI host not responding to stop endpoint command
- xhci_hcd: HC died; cleaning up
+ SRU Justification:
- Fix:
- Create a device link from any xHCI controller sharing the same PCIe
- root port as the APU display function. The link uses DL_FLAG_STATELESS
- and DL_FLAG_PM_RUNTIME to ensure the GPU completes its resume before
- the xHCI controller begins resuming USB devices.
+ [ Impact ]
+ Some AMD APU multi-function devices expose an integrated USB xHCI
+ controller. When the system resumes from suspend, the xHCI controller
+ can complete pci_pm_resume and start resuming USB devices while the GPU
+ is still in its much longer resume path. This race condition leads to
+ USB device resume failures followed by:
+ xhci_hcd ...: xHCI host not responding to stop endpoint command
+ xhci_hcd ...: HC died; cleaning up
- Test Plan:
- Build and boot the patched kernel on an AMD APU system with integrated
- xHCI controller. Verify that suspend/resume cycles no longer trigger
- xHCI host controller errors.
+ [ Fix ]
+ Backport upstream patch from mailing list:
+ -
https://lore.kernel.org/amd-gfx/[email protected]
- Where: kernel mailing list
-
https://lore.kernel.org/amd-gfx/[email protected]
+ [ Test Plan ]
+ 1. System with AMD APU and integrated xHCI controller
+ 2. Suspend system: systemctl suspend
+ 3. Resume and verify USB devices work correctly
+ 4. Check dmesg for no xHCI errors
- This is a backport of an upstream patch authored by Mario Limonciello.
+ [ Where problems could occur ]
+ Fix only affects SMU power dependency path.
+ It may break the AMDGPU and SMU.
- Backported branches:
- noble-linux-oem/oem-6.17-next
- resolute-linux-oem/oem-7.0-next
+ [ Other Info ]
+ SRU for OEM kernel only before it's landed in upstream.
** Changed in: hwe-next
Importance: Undecided => Medium
** Changed in: linux-oem-6.17 (Ubuntu)
Importance: Undecided => Medium
** Changed in: linux-oem-7.0 (Ubuntu)
Importance: Undecided => Medium
** Also affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Also affects: linux (Ubuntu Noble)
Importance: Undecided
Status: New
** Also affects: linux-oem-6.17 (Ubuntu Noble)
Importance: Undecided
Status: New
** Also affects: linux-oem-7.0 (Ubuntu Noble)
Importance: Undecided
Status: New
** Also affects: linux (Ubuntu Resolute)
Importance: Undecided
Status: New
** Also affects: linux-oem-6.17 (Ubuntu Resolute)
Importance: Undecided
Status: New
** Also affects: linux-oem-7.0 (Ubuntu Resolute)
Importance: Undecided
Status: New
** Also affects: linux (Ubuntu Stonking)
Importance: Undecided
Status: New
** Also affects: linux-oem-6.17 (Ubuntu Stonking)
Importance: Medium
Status: New
** Also affects: linux-oem-7.0 (Ubuntu Stonking)
Importance: Medium
Status: New
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https://bugs.launchpad.net/bugs/2160687
Title:
AMD APU USB xHCI controller fails to resume due to race with
GPU/display resume
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