Hi Can,
On Fri, Nov 8, 2019 at 1:50 PM Can Guo <cang@xxxxxxxxxxxxxx> wrote:
>
> 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.
>
> Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
> ---
Looks good, I hope this is tested on your platform.
Reviewed-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
> drivers/scsi/ufs/ufshcd.c | 20 +++++++-------------
> 1 file changed, 7 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 5950a7c..4df4136 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -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 +6333,13 @@ 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);
> + ufshcd_complete_requests(hba);
> spin_unlock_irqrestore(hba->host->host_lock, flags);
>
> /* scale up clocks to max frequency before full reinitialization */
> @@ -6369,7 +6373,6 @@ 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 +6382,6 @@ 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;
> }
>
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>
--
Regards,
Alim
