Re: [PATCH 3/4] scsi: ufs: Make the polling code report which command has been completed

[Bart Van Assche <bvanassche@xxxxxxx>]

On 4/12/24 02:14, Avri Altman wrote:
> > -static void ufshcd_mcq_process_cqe(struct ufs_hba *hba,
> > -                                  struct ufs_hw_queue *hwq)
> > +/* Returns true if and only if @compl_cmd has been completed. */
> > +static bool ufshcd_mcq_process_cqe(struct ufs_hba *hba,
> > +                                  struct ufs_hw_queue *hwq,
> > +                                  struct scsi_cmnd *compl_cmd)
> >   {
> >          struct cq_entry *cqe = ufshcd_mcq_cur_cqe(hwq);
> > -       int tag = ufshcd_mcq_get_tag(hba, cqe);
> >
> >          if (cqe->command_desc_base_addr) {
> > -               ufshcd_compl_one_cqe(hba, tag, cqe);
> > -               /* After processed the cqe, mark it empty (invalid) entry */
> > +               const int tag = ufshcd_mcq_get_tag(hba, cqe);
> > +               /* Mark the CQE as invalid. */
> >                  cqe->command_desc_base_addr = 0;
> > +               return ufshcd_compl_one_cqe(hba, tag, cqe, compl_cmd);
> >          }
> > +       return false;
> >   }
>
> Maybe elaborate on explaining why the tag isn't enough to designate the completing command?

Hi Avri,

Anything that uniquely identifies a SCSI command would work. I think
it's more a matter of making a choice rather than arguing why not using
the blk_mq_unique_tag_to_hwq() return value?

Thanks,

Bart.