On Mon, Nov 18, 2019 at 9:22 AM Can Guo <cang@xxxxxxxxxxxxxxxx> wrote:
>
> From: Can Guo <cang@xxxxxxxxxxxxxx>
>
> In UFS host reset and restore path, before probe, we stop and start the
> host controller once. After host controller is stopped, the pending
> requests, if any, are cleared from the doorbell, but no completion IRQ
> would be raised due to the hba is stopped.
> These pending requests shall be completed along with the first NOP_OUT
> command(as it is the first command which can raise a transfer completion
> IRQ) sent during probe.
> Since the OCSs of these pending requests are not SUCCESS(because they are
> not yet literally finished), their UPIUs shall be dumped. When there are
> multiple pending requests, the UPIU dump can be overwhelming and may lead
> to stability issues because it is in atomic context.
> Therefore, before probe, complete these pending requests right after host
> controller is stopped and silence the UPIU dump from them.
>
> Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
> ---
Tested-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
Please add all previous Ack/reviewed and tested-by tags so that we are
aware what need to be done for this patch.
Thanks
> drivers/scsi/ufs/ufshcd.c | 24 ++++++++++--------------
> drivers/scsi/ufs/ufshcd.h | 2 ++
> 2 files changed, 12 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 5950a7c..b92a3f4 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -4845,7 +4845,7 @@ static void ufshcd_slave_destroy(struct scsi_device *sdev)
> break;
> } /* end of switch */
>
> - if (host_byte(result) != DID_OK)
> + if ((host_byte(result) != DID_OK) && !hba->silence_err_logs)
> ufshcd_print_trs(hba, 1 << lrbp->task_tag, true);
> return result;
> }
> @@ -5404,8 +5404,8 @@ static void ufshcd_err_handler(struct work_struct *work)
>
> /*
> * if host reset is required then skip clearing the pending
> - * transfers forcefully because they will automatically get
> - * cleared after link startup.
> + * transfers forcefully because they will get cleared during
> + * host reset and restore
> */
> if (needs_reset)
> goto skip_pending_xfer_clear;
> @@ -6333,9 +6333,15 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
> int err;
> unsigned long flags;
>
> - /* Reset the host controller */
> + /*
> + * Stop the host controller and complete the requests
> + * cleared by h/w
> + */
> spin_lock_irqsave(hba->host->host_lock, flags);
> ufshcd_hba_stop(hba, false);
> + hba->silence_err_logs = true;
> + ufshcd_complete_requests(hba);
> + hba->silence_err_logs = false;
> spin_unlock_irqrestore(hba->host->host_lock, flags);
>
> /* scale up clocks to max frequency before full reinitialization */
> @@ -6369,7 +6375,6 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
> static int ufshcd_reset_and_restore(struct ufs_hba *hba)
> {
> int err = 0;
> - unsigned long flags;
> int retries = MAX_HOST_RESET_RETRIES;
>
> do {
> @@ -6379,15 +6384,6 @@ static int ufshcd_reset_and_restore(struct ufs_hba *hba)
> err = ufshcd_host_reset_and_restore(hba);
> } while (err && --retries);
>
> - /*
> - * After reset the door-bell might be cleared, complete
> - * outstanding requests in s/w here.
> - */
> - spin_lock_irqsave(hba->host->host_lock, flags);
> - ufshcd_transfer_req_compl(hba);
> - ufshcd_tmc_handler(hba);
> - spin_unlock_irqrestore(hba->host->host_lock, flags);
> -
> return err;
> }
>
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index e0fe247..1e51034 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -513,6 +513,7 @@ struct ufs_stats {
> * @uic_error: UFS interconnect layer error status
> * @saved_err: sticky error mask
> * @saved_uic_err: sticky UIC error mask
> + * @silence_err_logs: flag to silence error logs
> * @dev_cmd: ufs device management command information
> * @last_dme_cmd_tstamp: time stamp of the last completed DME command
> * @auto_bkops_enabled: to track whether bkops is enabled in device
> @@ -670,6 +671,7 @@ struct ufs_hba {
> u32 saved_err;
> u32 saved_uic_err;
> struct ufs_stats ufs_stats;
> + bool silence_err_logs;
>
> /* Device management request data */
> struct ufs_dev_cmd dev_cmd;
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>
--
Regards,
Alim
