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Alex Williamson authored
Assignment of NVIDIA Ampere-based GPUs have seen a regression since the below referenced commit, where the reduced D3hot transition delay appears to introduce a small window where a D3hot->D0 transition followed by a bus reset can wedge the device. The entire device is subsequently unavailable, returning -1 on config space read and is unrecoverable without a host reset. This has been observed with RTX A2000 and A5000 GPU and audio functions assigned to a Windows VM, where shutdown of the VM places the devices in D3hot prior to vfio-pci performing a bus reset when userspace releases the devices. The issue has roughly a 2-3% chance of occurring per shutdown. Restoring the HDA controller d3hot_delay to the effective value before the below commit has been shown to resolve the issue. NVIDIA confirms this change should be safe for all of their HDA controllers. Fixes: 3e347969 ("PCI/PM: Reduce D3hot delay with usleep_range()") Link: https://lore.kernel.org/r/20230413194042.605768-1-alex.williamson@redhat.comReported-by:
Zhiyi Guo <zhguo@redhat.com> Signed-off-by:
Alex Williamson <alex.williamson@redhat.com> Signed-off-by:
Bjorn Helgaas <bhelgaas@google.com> Reviewed-by:
Tarun Gupta <targupta@nvidia.com> Cc: Abhishek Sahu <abhsahu@nvidia.com> Cc: Tarun Gupta <targupta@nvidia.com>
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