Re: [PATCH 12/24] scsi: ufs: core: Rework ufshcd_mcq_compl_pending_transfer()

["Peter Wang (王信友)" <peter.wang@mediatek.com>]

On Thu, 2025-04-17 at 14:33 -0700, Bart Van Assche wrote:
> Hi Peter,
> 
> My understanding is that the function modified by patch 12/24,
> ufshcd_mcq_compl_pending_transfer(), is only called by the UFS error
> handler. The UFS error handler is only activated after all pending
> requests have completed (MQ_RQ_IDLE) or timed out (MQ_RQ_STARTED).
> No requests should have the state MQ_RQ_COMPLETE when the error
> handler
> is activated.
> 
> Thanks,
> 
> Bart.

Hi Bart,

Yes, ufshcd_mcq_compl_pending_transfer() is only called form error
handler.
Consider a situation where a UIC error occurs and triggers the error
handler, 
followed by receiving a request complete interrupt. 
At this point, the error handler might check this request that hasn't
completed yet, 
and just as it is about to complete it, the tag has already been
completed by 
the ISR. This request status may in MQ_RQ_COMPLETE.

Thanks.
Peter