ACK: [SRU][unstabe/Q/P/N][PATCH 0/1] nvme no longer detected on

[Zixing Liu]

> Date: Tue, 19 Aug 2025 16:21:22 +0800
> From: Hui Wang <hui.wang at canonical.com>
>
> 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(-)
>
> --
> 2.34.1
>

Acked-by: Zixing Liu <zixing.liu at canonical.com>