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().
Thanks,
Stanley Chu
