Re: [PATCH for-linus] PCI/AER: Skip error recovery on false alarms

[sashiko-bot@kernel.org]

> Alex is seeing a probe failure of the amdgpu driver after the Root Port
> above an AMD Navi10 GPU has been reset.  The reset was performed to
> recover from a Firmware First reported Fatal Error.
> 
> However all status registers in the Root Port's AER Extended Capability
> are blank, so apparently the platform firmware raised a false alarm.
> 
> The issue is only occurring since commit eddba19b8b5f ("PCI/AER: Support
> Advisory Non-Fatal Errors").  It looks like enabling Advisory Non-Fatal
> Errors causes code paths to be exercised in platform firmware which
> were never validated before.
> 
> Skip error recovery on false alarms, i.e. if no unmasked errors were
> actually signaled.
> 
> Note that this will also skip recovery if both the Status and Mask
> registers are "all ones", as would be the case for inaccessible devices.
> However that seems justified because it would imply either a hot-unplug
> event or a Surprise Down Error further up in the hierarchy.  Interfering
> with recovery from that seems uncalled for.
> 
> Fixes: eddba19b8b5f ("PCI/AER: Support Advisory Non-Fatal Errors")
> Reported-by: Alex Deucher <alexander.deucher@amd.com>
> Tested-by: Alex Deucher <alexander.deucher@amd.com>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=222095
> Signed-off-by: Lukas Wunner <lukas@wunner.de>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/0552ed277e40a288e0157af799257ee6ec722534.1791460615.git.lukas@wunner.de?part=1