On 10/06/21 7:43 am, Can Guo wrote:
> Commit cb7e6f05fce67c965194ac04467e1ba7bc70b069 ("scsi: ufs: core: Enable
> power management for wlun") moves UFS operations out of ufshcd_resume(), so
> in error handling preparation, if ufshcd hba has failed to resume, there is
> no point to re-enable IRQ/clk/pwr.
I am not sure how cb7e6f05fce67c965194ac04467e1ba7bc70b069 made things any
different, but what I really wonder is why we don't just do recovery
directly in __ufshcd_wl_suspend() and __ufshcd_wl_resume() and strip all
the PM complexity out of ufshcd_err_handling()?
>
> Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
> ---
> drivers/scsi/ufs/ufshcd.c | 58 +++++++++++++++++++++++++----------------------
> 1 file changed, 31 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 7dc0fda..0afad6b 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -2727,8 +2727,8 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
> break;
> case UFSHCD_STATE_EH_SCHEDULED_FATAL:
> /*
> - * pm_runtime_get_sync() is used at error handling preparation
> - * stage. If a scsi cmd, e.g. the SSU cmd, is sent from hba's
> + * ufshcd_rpm_get_sync() is used at error handling preparation
> + * stage. If a scsi cmd, e.g., the SSU cmd, is sent from the
> * PM ops, it can never be finished if we let SCSI layer keep
> * retrying it, which gets err handler stuck forever. Neither
> * can we let the scsi cmd pass through, because UFS is in bad
> @@ -5915,29 +5915,26 @@ static void ufshcd_clk_scaling_suspend(struct ufs_hba *hba, bool suspend)
> }
> }
>
> -static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
> +static int ufshcd_err_handling_prepare(struct ufs_hba *hba)
> {
> + /*
> + * Exclusively call pm_runtime_get_sync(hba->dev) once, in case
> + * following ufshcd_rpm_get_sync() fails.
> + */
> + pm_runtime_get_sync(hba->dev);
> + /* End of the world. */
> + if (pm_runtime_suspended(hba->dev)) {
> + pm_runtime_put(hba->dev);
> + return -EINVAL;
> + }
> +
> + ufshcd_set_eh_in_progress(hba);
> ufshcd_rpm_get_sync(hba);
> - if (pm_runtime_status_suspended(&hba->sdev_ufs_device->sdev_gendev) ||
> + if (pm_runtime_suspended(&hba->sdev_ufs_device->sdev_gendev) ||
> hba->is_wl_sys_suspended) {
> - enum ufs_pm_op pm_op;
> + enum ufs_pm_op pm_op = hba->is_wl_sys_suspended ?
> + UFS_SYSTEM_PM : UFS_RUNTIME_PM;
>
> - /*
> - * Don't assume anything of resume, if
> - * resume fails, irq and clocks can be OFF, and powers
> - * can be OFF or in LPM.
> - */
> - ufshcd_setup_hba_vreg(hba, true);
> - ufshcd_setup_vreg(hba, true);
> - ufshcd_config_vreg_hpm(hba, hba->vreg_info.vccq);
> - ufshcd_config_vreg_hpm(hba, hba->vreg_info.vccq2);
> - ufshcd_hold(hba, false);
> - if (!ufshcd_is_clkgating_allowed(hba)) {
> - ufshcd_setup_clocks(hba, true);
> - ufshcd_enable_irq(hba);
> - }
> - ufshcd_release(hba);
> - pm_op = hba->is_wl_sys_suspended ? UFS_SYSTEM_PM : UFS_RUNTIME_PM;
> ufshcd_vops_resume(hba, pm_op);
> } else {
> ufshcd_hold(hba, false);
> @@ -5951,22 +5948,25 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
> down_write(&hba->clk_scaling_lock);
> up_write(&hba->clk_scaling_lock);
> cancel_work_sync(&hba->eeh_work);
> + return 0;
> }
>
> static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
> {
> + ufshcd_clear_eh_in_progress(hba);
> ufshcd_scsi_unblock_requests(hba);
> ufshcd_release(hba);
> if (ufshcd_is_clkscaling_supported(hba))
> ufshcd_clk_scaling_suspend(hba, false);
> ufshcd_clear_ua_wluns(hba);
> ufshcd_rpm_put(hba);
> + pm_runtime_put(hba->dev);
> }
>
> static inline bool ufshcd_err_handling_should_stop(struct ufs_hba *hba)
> {
> return (!hba->is_powered || hba->shutting_down ||
> - !hba->sdev_ufs_device ||
> + !hba->sdev_ufs_device || hba->is_sys_suspended ||
> hba->ufshcd_state == UFSHCD_STATE_ERROR ||
> (!(hba->saved_err || hba->saved_uic_err || hba->force_reset ||
> ufshcd_is_link_broken(hba))));
> @@ -6052,9 +6052,13 @@ static void ufshcd_err_handler(struct work_struct *work)
> up(&hba->host_sem);
> return;
> }
> - ufshcd_set_eh_in_progress(hba);
> spin_unlock_irqrestore(hba->host->host_lock, flags);
> - ufshcd_err_handling_prepare(hba);
> + if (ufshcd_err_handling_prepare(hba)) {
> + dev_err(hba->dev, "%s: error handling preparation failed\n",
> + __func__);
> + up(&hba->host_sem);
> + return;
> + }
> /* Complete requests that have door-bell cleared by h/w */
> ufshcd_complete_requests(hba);
> spin_lock_irqsave(hba->host->host_lock, flags);
> @@ -6198,7 +6202,6 @@ static void ufshcd_err_handler(struct work_struct *work)
> dev_err_ratelimited(hba->dev, "%s: exit: saved_err 0x%x saved_uic_err 0x%x",
> __func__, hba->saved_err, hba->saved_uic_err);
> }
> - ufshcd_clear_eh_in_progress(hba);
> spin_unlock_irqrestore(hba->host->host_lock, flags);
> ufshcd_err_handling_unprepare(hba);
> up(&hba->host_sem);
> @@ -8999,6 +9002,9 @@ static int __ufshcd_wl_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>
> /* Enable Auto-Hibernate if configured */
> ufshcd_auto_hibern8_enable(hba);
> +
> + hba->clk_gating.is_suspended = false;
> + ufshcd_release(hba);
> goto out;
>
> set_old_link_state:
> @@ -9008,8 +9014,6 @@ static int __ufshcd_wl_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
> out:
> if (ret)
> ufshcd_update_evt_hist(hba, UFS_EVT_WL_RES_ERR, (u32)ret);
> - hba->clk_gating.is_suspended = false;
> - ufshcd_release(hba);
> hba->wl_pm_op_in_progress = false;
> return ret <= 0 ? ret : -EINVAL;
> }
>
