Re: [PATCH v5 5/6] scsi: ufs: core: Remove completed-without-interrupt path in ufshcd_abort()

[Bean Huo <beanhuo@iokpp.de>]

On Thu, 2026-10-22 at 11:44 +0800, Stanley Jhu wrote:
> In SDB mode, a command that times out right as the controller finishes
> it can be completed twice:
> 
> 1. The command times out and scsi_timeout() schedules ufshcd_abort().
> 2. The controller finishes the command and clears its doorbell bit in
>    REG_UTP_TRANSFER_REQ_DOOR_BELL, while the completion handler has not
>    yet cleared BIT(tag) in hba->outstanding_reqs.
> 3. ufshcd_abort() sees the doorbell bit clear and calls
>    __ufshcd_transfer_req_compl() without clearing BIT(tag) in
>    hba->outstanding_reqs.
> 4. The normal completion handler or the logical unit reset that follows
>    sees BIT(tag) still set in hba->outstanding_reqs and completes the
>    same command a second time.
> 
> This branch only exists for a rare corner case, a completion interrupt
> that is lost or arrives late. Remove it to simplify the abort path and
> leave such a command to the SCSI error handler, like any other command
> that cannot be aborted. The cost is a slower recovery in this corner
> case, which is acceptable since it only happens after a timeout.
> 
> Fixes: 169f5eb28869 ("scsi: ufs: Optimize SCSI command processing")
> Cc: stable@vger.kernel.org
> Link: https://lore.kernel.org/r/fdb5c391-01ef-4a23-94c2-4f3853909348@acm.org
> Signed-off-by: Stanley Jhu <stanleyjhu@google.com>

Reviewed-by: Bean Huo <beanhuo@micron.com>