Re: [PATCH v3 4/9] scsi: ufs: Complete the cmd before returning in queuecommand

[Can Guo]

On 2021-06-12 04:52, Bart Van Assche wrote:
> On 6/9/21 9:43 PM, Can Guo wrote:
> > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> > index 0c9d2ee..7dc0fda 100644
> > --- a/drivers/scsi/ufs/ufshcd.c
> > +++ b/drivers/scsi/ufs/ufshcd.c
> > @@ -2758,6 +2758,16 @@ static int ufshcd_queuecommand(struct Scsi_Host 
> > *host, struct scsi_cmnd *cmd)
> >  		goto out;
> >  	}
> >
> > +	if (unlikely(test_bit(tag, &hba->outstanding_reqs))) {
> > +		if (hba->wl_pm_op_in_progress) {
> > +			set_host_byte(cmd, DID_BAD_TARGET);
> > +			cmd->scsi_done(cmd);
> > +		} else {
> > +			err = SCSI_MLQUEUE_HOST_BUSY;
> > +		}
> > +		goto out;
> > +	}
> > +
> >  	hba->req_abort_count = 0;
> >
> >  	err = ufshcd_hold(hba, true);
> > @@ -2768,15 +2778,6 @@ static int ufshcd_queuecommand(struct Scsi_Host 
> > *host, struct scsi_cmnd *cmd)
> >  	WARN_ON(ufshcd_is_clkgating_allowed(hba) &&
> >  		(hba->clk_gating.state != CLKS_ON));
> >
> > -	if (unlikely(test_bit(tag, &hba->outstanding_reqs))) {
> > -		if (hba->wl_pm_op_in_progress)
> > -			set_host_byte(cmd, DID_BAD_TARGET);
> > -		else
> > -			err = SCSI_MLQUEUE_HOST_BUSY;
> > -		ufshcd_release(hba);
> > -		goto out;
> > -	}
> > -
> >  	lrbp = &hba->lrb[tag];
> >  	WARN_ON(lrbp->cmd);
> >  	lrbp->cmd = cmd;
>
> Can the code under "if (unlikely(test_bit(tag,
> &hba->outstanding_reqs)))" be deleted instead of moving it? I don't
> think that it is useful to verify whether the block layer tag allocator
> works correctly. Additionally, I'm not aware of any similar code in any
> other SCSI LLD.

ufshcd_abort() aborts PM requests differently from other requests -
it simply evicts the cmd from lrbp [1], schedules error handler and
returns SUCCESS (the reason why I am doing it this way is in patch #8).

After ufshcd_abort() returns, the tag shall be released, the logic
here is to prevent subsequent cmds re-use the lrbp [1] before error
handler recovers the device and host.

Thanks,

Can Guo.

> Thanks,
>
> Bart.