Reviewed-by: Gilad Broner <gbroner@xxxxxxxxxxxxxx>
> Hibern8 exit can be called from 3 different context:
> - ufshcd_hibern8_exit_work
> - ufshcd_ungate_work
> - runtime/system resume
>
> If hibern8 exit fails for some reason then we try to bring the link to
> active state by link startup but this recovery mechanism results into
> deadlock or errors from first 2 context listed above. This change fixes
> the recovery by adding proper error handling mechanism.
>
> Signed-off-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
> Signed-off-by: Yaniv Gardi <ygardi@xxxxxxxxxxxxxx>
>
> ---
> drivers/scsi/ufs/ufshcd.c | 58
> +++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 53 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index ed134d6..60ba729 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -610,6 +610,11 @@ int ufshcd_hold(struct ufs_hba *hba, bool async)
> spin_lock_irqsave(hba->host->host_lock, flags);
> hba->clk_gating.active_reqs++;
>
> + if (ufshcd_eh_in_progress(hba)) {
> + spin_unlock_irqrestore(hba->host->host_lock, flags);
> + return 0;
> + }
> +
> start:
> switch (hba->clk_gating.state) {
> case CLKS_ON:
> @@ -725,7 +730,8 @@ static void __ufshcd_release(struct ufs_hba *hba)
> if (hba->clk_gating.active_reqs || hba->clk_gating.is_suspended
> || hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL
> || hba->lrb_in_use || hba->outstanding_tasks
> - || hba->active_uic_cmd || hba->uic_async_done)
> + || hba->active_uic_cmd || hba->uic_async_done
> + || ufshcd_eh_in_progress(hba))
> return;
>
> hba->clk_gating.state = REQ_CLKS_OFF;
> @@ -1363,6 +1369,13 @@ static int ufshcd_queuecommand(struct Scsi_Host
> *host, struct scsi_cmnd *cmd)
> cmd->scsi_done(cmd);
> goto out_unlock;
> }
> +
> + /* if error handling is in progress, don't issue commands */
> + if (ufshcd_eh_in_progress(hba)) {
> + set_host_byte(cmd, DID_ERROR);
> + cmd->scsi_done(cmd);
> + goto out_unlock;
> + }
> spin_unlock_irqrestore(hba->host->host_lock, flags);
>
> /* acquire the tag to make sure device cmds don't use it */
> @@ -2393,6 +2406,31 @@ out:
> return ret;
> }
>
> +static int ufshcd_link_recovery(struct ufs_hba *hba)
> +{
> + int ret;
> + unsigned long flags;
> +
> + spin_lock_irqsave(hba->host->host_lock, flags);
> + hba->ufshcd_state = UFSHCD_STATE_RESET;
> + ufshcd_set_eh_in_progress(hba);
> + spin_unlock_irqrestore(hba->host->host_lock, flags);
> +
> + ret = ufshcd_host_reset_and_restore(hba);
> +
> + spin_lock_irqsave(hba->host->host_lock, flags);
> + if (ret)
> + hba->ufshcd_state = UFSHCD_STATE_ERROR;
> + ufshcd_clear_eh_in_progress(hba);
> + spin_unlock_irqrestore(hba->host->host_lock, flags);
> +
> + if (ret)
> + dev_err(hba->dev, "%s: link recovery failed, err %d",
> + __func__, ret);
> +
> + return ret;
> +}
> +
> static int __ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
> {
> int ret;
> @@ -2401,10 +2439,18 @@ static int __ufshcd_uic_hibern8_enter(struct
> ufs_hba *hba)
> uic_cmd.command = UIC_CMD_DME_HIBER_ENTER;
> ret = ufshcd_uic_pwr_ctrl(hba, &uic_cmd);
>
> - if (ret)
> + if (ret) {
> dev_err(hba->dev, "%s: hibern8 enter failed. ret = %d\n",
> __func__, ret);
>
> + /*
> + * If link recovery fails then return error so that caller
> + * don't retry the hibern8 enter again.
> + */
> + if (ufshcd_link_recovery(hba))
> + ret = -ENOLINK;
> + }
> +
> return ret;
> }
>
> @@ -2429,8 +2475,9 @@ static int ufshcd_uic_hibern8_exit(struct ufs_hba
> *hba)
> uic_cmd.command = UIC_CMD_DME_HIBER_EXIT;
> ret = ufshcd_uic_pwr_ctrl(hba, &uic_cmd);
> if (ret) {
> - ufshcd_set_link_off(hba);
> - ret = ufshcd_host_reset_and_restore(hba);
> + dev_err(hba->dev, "%s: hibern8 exit failed. ret = %d\n",
> + __func__, ret);
> + ret = ufshcd_link_recovery(hba);
> }
>
> return ret;
> @@ -4382,7 +4429,6 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
> /* UFS device is also active now */
> ufshcd_set_ufs_dev_active(hba);
> ufshcd_force_reset_auto_bkops(hba);
> - hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
> hba->wlun_dev_clr_ua = true;
>
> if (ufshcd_get_max_pwr_mode(hba)) {
> @@ -4396,6 +4442,8 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
> __func__, ret);
> }
>
> + /* set the state as operational after switching to desired gear */
> + hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
> /*
> * If we are in error handling context or in power management callbacks
> * context, no need to scan the host
> --
> 1.8.5.2
>
> --
> QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
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