[PATCH] nvme-pci: Add quirk for broken MSIs

[Sean Anderson]

On 4/22/24 13:15, Sean Anderson wrote:
> On 4/22/24 12:49, Keith Busch wrote:
>> On Mon, Apr 22, 2024 at 12:28:23PM -0400, Sean Anderson wrote:
>>> Sandisk SN530 NVMe drives have broken MSIs. On systems without MSI-X
>>> support, all commands time out resulting in the following message:
>>> 
>>> nvme nvme0: I/O tag 12 (100c) QID 0 timeout, completion polled
>>> 
>>> These timeouts cause the boot to take an excessively-long time (over 20
>>> minutes) while the initial command queue is flushed.
>>> 
>>> Address this by adding a quirk for drives with buggy MSIs. The lspci
>>> output for this device (recorded on a system with MSI-X support) is:
>> 
>> Based on your description, the patch looks good. This will fallback to
>> legacy emulated pin interrupts, and that's better than timeout polling,
>> but will still appear sluggish compared to MSI's. Is there an errata
>> from the vendor on this? I'm just curious if the bug is at the Device ID
>> level, and not something we could constrain to a particular model or
>> firmware revision. 
> 
> I wasn't able to find any errata for this drive. I wasn't able to
> determine if there are any firmware updates for this drive (FWIW I have
> version "21160001"). I'll contact WD and see if they know about this
> issue.

Well, the response from WD support was "we don't support Linux, and if
we did there aren't any bugs in the drive anyway".

--Sean