Re: [PATCH v10 2/2] ufs: core: requeue aborted request

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

On Tue, 2024-10-08 at 11:29 -0700, Bart Van Assche wrote:
> Hi Peter,
> 
> I think what you wrote applies to MCQ mode only. In my previous email
> I clearly referred to "legacy mode" (SDB mode). Summarizing my
> previous
> email, I think that in legacy mode it is possible that
> ufshcd_release()
> is called twice while it only should be called once. Here are the
> possible solutions I see:
> * Add a function to the SCSI core for setting SCMD_STATE_COMPLETE.
> This
>    may be controversial since no other SCSI LLD needs this
> functionality.
> * Changing the error handling approach in the UFS driver to the same
>    approach other SCSI LLDs use: instead of using queue_work() to
>    activate the error handler, call scsi_schedule_eh(). This will
> cause
>    the error handler to be activated later, namely after all pending
>    commands have timed out instead of aborting any pending commands
>    first.
> * Add a variant of scsi_schedule_eh() to the SCSI core that
> accelerates
>    error handling by calling scsi_timeout() on all pending commands.
> 
> Thanks,
> 
> Bart.
> 

Hi Bart,

Yes, this patch is only for MCQ mode, because only MCQ mode 
receives OCS: ABORTED, right? This patch doesn't modify 
any of the Legacy mode flows, does it?

Additionally, I still don't understand why you say there would 
be an issue with legacy mode having duplicate ufshcd_release(hba) 
calls. As I mentioned before, it is protected by the 
outstanding_lock. Could you please clarify the detailed 
error flow?

Furthermore, even if there is an issue with Legacy mode, it 
should be addressed by a separate patch, not by this one, which is 
intended to resolve the MCQ mode issue. We shouldn't mix two 
different issues together, don't you agree?

Thanks
Peter