On Mon, May 22, 2023 at 2:48 PM Stanley Chu <chu.stanley@xxxxxxxxx> wrote:
>
> Hi Bao,
>
> Bao D. Nguyen <quic_nguyenb@xxxxxxxxxxx> 於 2023年5月12日 週五 下午2:34寫道：
> >
> > Add support for error handling for MCQ mode.
> >
> > Signed-off-by: Bao D. Nguyen <quic_nguyenb@xxxxxxxxxxx>
> > ---
> > drivers/ufs/core/ufshcd.c | 85 +++++++++++++++++++++++++++++++++++++++++------
> > 1 file changed, 74 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> > index ec07e49..9345118 100644
> > --- a/drivers/ufs/core/ufshcd.c
> > +++ b/drivers/ufs/core/ufshcd.c
> > @@ -3148,6 +3148,16 @@ static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba,
> > err = -ETIMEDOUT;
> > dev_dbg(hba->dev, "%s: dev_cmd request timedout, tag %d\n",
> > __func__, lrbp->task_tag);
> > +
> > + /* MCQ mode */
> > + if (is_mcq_enabled(hba)) {
> > + err = ufshcd_clear_cmd(hba, lrbp->task_tag);
> > + if (!err)
> > + hba->dev_cmd.complete = NULL;
>
> How about always clearing hba->dev_cmd.complete? If ufshcd_clear_cmd()
> fails (for example, times out), "complete" should be cleared, similar
> to the "pending" case in the SDB path.
>
> > + return err;
> > + }
> > +
> > + /* SDB mode */
> > if (ufshcd_clear_cmd(hba, lrbp->task_tag) == 0) {
> > /* successfully cleared the command, retry if needed */
> > err = -EAGAIN;
> > @@ -5581,6 +5591,10 @@ static int ufshcd_poll(struct Scsi_Host *shost, unsigned int queue_num)
> > */
> > static irqreturn_t ufshcd_transfer_req_compl(struct ufs_hba *hba)
> > {
> > + struct ufshcd_lrb *lrbp;
> > + u32 hwq_num, utag;
> > + int tag;
> > +
> > /* Resetting interrupt aggregation counters first and reading the
> > * DOOR_BELL afterward allows us to handle all the completed requests.
> > * In order to prevent other interrupts starvation the DB is read once
> > @@ -5599,7 +5613,22 @@ static irqreturn_t ufshcd_transfer_req_compl(struct ufs_hba *hba)
> > * Ignore the ufshcd_poll() return value and return IRQ_HANDLED since we
> > * do not want polling to trigger spurious interrupt complaints.
> > */
> > - ufshcd_poll(hba->host, UFSHCD_POLL_FROM_INTERRUPT_CONTEXT);
> > + if (!is_mcq_enabled(hba)) {
> > + ufshcd_poll(hba->host, UFSHCD_POLL_FROM_INTERRUPT_CONTEXT);
> > + goto out;
> > + }
> > +
> > + /* MCQ mode */
> > + for (tag = 0; tag < hba->nutrs; tag++) {
> > + lrbp = &hba->lrb[tag];
> > + if (ufshcd_cmd_inflight(lrbp->cmd)) {
> > + utag = blk_mq_unique_tag(scsi_cmd_to_rq(lrbp->cmd));
> > + hwq_num = blk_mq_unique_tag_to_hwq(utag);
> > + ufshcd_poll(hba->host, hwq_num);
> > + }
> > + }
>
> In SDB mode, the DOOR_BELL is reset by ufshcd_hba_stop(). All bits
> that were previously set in DOOR_BELL are also set in "completed_reqs"
> in ufshcd_poll(). This allows ufshcd_poll() to handle all outstanding
> requests properly.
>
> However, in MCQ mode, the CQ tail registers cannot provide the same
> information after they are reset. Hence, they cannot be properly
> referenced by ufshcd_poll().
A fixed version sample is as follows and has been tested on our end.
struct scsi_cmnd *cmd;
for (tag = 0; tag < hba->nutrs; tag++) {
lrbp = &hba->lrb[tag];
cmd = lrbp->cmd;
if (ufshcd_cmd_inflight(cmd)) {
set_host_byte(cmd, DID_ERROR);
ufshcd_release_scsi_cmd(hba, lrbp);
scsi_done(cmd);
}
}
Thanks,
Stanley Chu
