Re: [PATCH] PCI: Don't read config space of disconnected devices in ext cap search

[sashiko-bot@kernel.org]

> Commit 4d909bf1a53e ("PCI: Refactor extended capability search into
> PCI_FIND_NEXT_EXT_CAP()") moved the extended capability search from the
> device config accessor to the bus config accessor. The bus accessor
> skips the disconnected device check, so walking the extended capability
> list of a device already marked disconnected (surprise removal, AER/DPC
> recovery) now issues real config reads to it. A dead device returns all
> ones for the first extended capability header. That decodes as a next
> pointer to the last dword of config space, so the walk keeps re-reading
> that dword until its TTL expires, roughly 480 config reads per call.
> 
> Restore the device accessor so the walk stops without touching hardware
> once the device is disconnected.
> 
> Fixes: 4d909bf1a53e ("PCI: Refactor extended capability search into PCI_FIND_NEXT_EXT_CAP()")
> Cc: stable@vger.kernel.org
> Signed-off-by: Anthony Pighin <anthony.pighin@nokia.com>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261019165159.1268120-1-anthony.pighin@nokia.com?part=1