[SRU][unstabe/Q/P/N][PATCH 0/1] nvme no longer detected on boot after upgrade to 6.8.0-60

[Hui Wang]

BugLink: https://bugs.launchpad.net/bugs/2111521

[Impact]

An Intel nvme stops working after upgrade to noble 6.8.0-60, that is because
a upstream stable commit d591f6804e7e ("PCI: Wait for device readiness with
Configuration RRS") introduced this regression, and other than noble, the
ubuntu plucky, questing and mainline kernel are all impacted. So far a formal
fix is not ready yet, PCI maintainer has been working on it for almost 1.5
month, the ubuntu users want the bug get fixed asap, otherwise their servers
couldn't upgrade the ubuntu kernel.

As a temporary fix, I wrote a SAUCE patch to apply a quirk to this Intel nvme
device. After the mainline kernel has a formal fix, we could revert this SAUCE
patch and introduce the formal one.

Upstream mailing list discussion:
https://lore.kernel.org/linux-pci/20250611101442.387378-1-hui.wang@canonical.com/T/

[Fix]

apply a SAUCE patch, this will set a specific quirk to this Intel nvme device


[Test]

I patched noble and unstable kernels and built them, then shared the deb to
bug reporters, they tested with the patched kernel, the nvme worked as before


[Where problems could occur]

This quirk is specific to the Intel nvme device 8086:0a54, so it is safe to
other devices, if it has chance to introduce regression, it will make this
Intel nvme device stop working if the nvme connects to a differnt VMD or pci
root port, but this regression chance is very low since this quirk just disable
the RRS polling, and let pci_dev_wait() work as before.


Hui Wang (1):
  UBUNTU: SAUCE: PCI: Disable RRS polling for Intel SSDPE2KX020T8 nvme

 drivers/pci/probe.c  |  3 ++-
 drivers/pci/quirks.c | 18 ++++++++++++++++++
 include/linux/pci.h  |  2 ++
 3 files changed, 22 insertions(+), 1 deletion(-)

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2.34.1