Re: [PATCH for-rc 2/7] RDMA/bnxt_re: Honor a completion that races with a wait timeout

[sashiko-bot@kernel.org]

> If the wait helper gives up (timeout or firmware stall) and the CREQ
> tasklet processes the command before the waiter takes hwq->lock, the
> response is already copied into the caller's buffer and is_in_used is
> clear. The waiter still returns -ETIMEDOUT and may set
> FIRMWARE_STALL_DETECTED, and for CREATE_AH the handler skips
> destroy_timedout_ah() because the waiter was alive, so the AH leaks in
> firmware.
> 
> Under the lock, if the slot no longer holds this command's response
> buffer, a completion was delivered. Use its status instead of failing.
> 
> To keep that check valid, never reuse a cookie slot that is still in
> use: __send_message() returns -EAGAIN and __send_message_no_waiter()
> drops the internal command.
> 
> A slot stays in use only while its completion is outstanding. If that
> completion never arrives, the cause is a PCI error or firmware still
> processing the command, so there is no point in posting more commands.
> Continuing to return -EAGAIN until firmware completes the command in
> order is intended; otherwise recovery is initiated.
> 
> An internal destroy_ah dropped for the same reason leaks the AH in
> firmware; this is accepted and the comment in
> bnxt_qplib_service_creq() is updated to say so.
> 
> Fixes: 691eb7c6110f ("RDMA/bnxt_re: handle command completions after driver detect a timedout")
> Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261028113404.33289-1-selvin.xavier@broadcom.com?part=2