From c72e79c0ad2bd7efb1cf84f630f59daf9ba8c510 Mon Sep 17 00:00:00 2001 From: Can Guo Date: Sun, 9 Aug 2020 05:15:52 -0700 Subject: [PATCH] scsi: ufs: Recover HBA runtime PM error in error handler The current error handler can not recover HBA runtime PM error if ufshcd_suspend/resume has failed due to UFS errors, e.g. hibern8 enter/exit error or SSU cmd error. When this happens, error handler may fail performing a full reset and restore because error handler always assumes that power, IRQs and clocks are ready after pm_runtime_get_sync returns, but actually they are not if ufshcd_resume fails[1]. If ufschd_suspend/resume fails due to UFS errors, runtime PM framework saves the error value to dev.power.runtime_error. After that, HBA dev runtime suspend/resume would not be invoked anymore unless runtime_error is cleared[2]. In case of ufshcd_suspend/resume fails due to UFS errors, for scenario [1], error handler cannot assume anything of pm_runtime_get_sync, meaning error handler should explicitly turn ON powers, IRQs and clocks again. To get the HBA runtime PM work as regard for scenario [2], error handler can clear the runtime_error by calling pm_runtime_set_active() if full reset and restore succeeds. And, more important, if pm_runtime_set_active() returns no error, which means runtime_error has been cleared, we also need to resume those scsi devices under HBA in case any of them has failed to be resumed due to HBA runtime resume failure. This is to unblock blk_queue_enter in case there are bios waiting inside it. Link: https://lore.kernel.org/r/1596975355-39813-7-git-send-email-cang@codeaurora.org Reviewed-by: Bean Huo Reviewed-by: Asutosh Das Signed-off-by: Can Guo Signed-off-by: Martin K. Petersen --- drivers/scsi/ufs/ufshcd.c | 108 ++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 99 insertions(+), 9 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 2604016..ed24582 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -15,6 +15,7 @@ #include #include #include +#include #include "ufshcd.h" #include "ufs_quirks.h" #include "unipro.h" @@ -229,6 +230,10 @@ static irqreturn_t ufshcd_intr(int irq, void *__hba); static int ufshcd_change_power_mode(struct ufs_hba *hba, struct ufs_pa_layer_attr *pwr_mode); static void ufshcd_schedule_eh_work(struct ufs_hba *hba); +static int ufshcd_setup_hba_vreg(struct ufs_hba *hba, bool on); +static int ufshcd_setup_vreg(struct ufs_hba *hba, bool on); +static inline int ufshcd_config_vreg_hpm(struct ufs_hba *hba, + struct ufs_vreg *vreg); static int ufshcd_wb_buf_flush_enable(struct ufs_hba *hba); static int ufshcd_wb_buf_flush_disable(struct ufs_hba *hba); static int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable); @@ -5553,6 +5558,84 @@ static inline void ufshcd_schedule_eh_work(struct ufs_hba *hba) } } +static void ufshcd_err_handling_prepare(struct ufs_hba *hba) +{ + pm_runtime_get_sync(hba->dev); + if (pm_runtime_suspended(hba->dev)) { + /* + * Don't assume anything of pm_runtime_get_sync(), if + * resume fails, irq and clocks can be OFF, and powers + * can be OFF or in LPM. + */ + ufshcd_setup_hba_vreg(hba, true); + ufshcd_enable_irq(hba); + 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_release(hba); + ufshcd_vops_resume(hba, UFS_RUNTIME_PM); + } else { + ufshcd_hold(hba, false); + if (hba->clk_scaling.is_allowed) { + cancel_work_sync(&hba->clk_scaling.suspend_work); + cancel_work_sync(&hba->clk_scaling.resume_work); + ufshcd_suspend_clkscaling(hba); + } + } +} + +static void ufshcd_err_handling_unprepare(struct ufs_hba *hba) +{ + ufshcd_release(hba); + if (hba->clk_scaling.is_allowed) + ufshcd_resume_clkscaling(hba); + pm_runtime_put(hba->dev); +} + +static inline bool ufshcd_err_handling_should_stop(struct ufs_hba *hba) +{ + return (hba->ufshcd_state == UFSHCD_STATE_ERROR || + (!(hba->saved_err || hba->saved_uic_err || hba->force_reset || + ufshcd_is_link_broken(hba)))); +} + +#ifdef CONFIG_PM +static void ufshcd_recover_pm_error(struct ufs_hba *hba) +{ + struct Scsi_Host *shost = hba->host; + struct scsi_device *sdev; + struct request_queue *q; + int ret; + + /* + * Set RPM status of hba device to RPM_ACTIVE, + * this also clears its runtime error. + */ + ret = pm_runtime_set_active(hba->dev); + /* + * If hba device had runtime error, we also need to resume those + * scsi devices under hba in case any of them has failed to be + * resumed due to hba runtime resume failure. This is to unblock + * blk_queue_enter in case there are bios waiting inside it. + */ + if (!ret) { + shost_for_each_device(sdev, shost) { + q = sdev->request_queue; + if (q->dev && (q->rpm_status == RPM_SUSPENDED || + q->rpm_status == RPM_SUSPENDING)) + pm_request_resume(q->dev); + } + } +} +#else +static inline void ufshcd_recover_pm_error(struct ufs_hba *hba) +{ +} +#endif + /** * ufshcd_err_handler - handle UFS errors that require s/w attention * @work: pointer to work structure @@ -5570,9 +5653,7 @@ static void ufshcd_err_handler(struct work_struct *work) hba = container_of(work, struct ufs_hba, eh_work); spin_lock_irqsave(hba->host->host_lock, flags); - if (hba->ufshcd_state == UFSHCD_STATE_ERROR || - (!(hba->saved_err || hba->saved_uic_err || hba->force_reset || - ufshcd_is_link_broken(hba)))) { + if (ufshcd_err_handling_should_stop(hba)) { if (hba->ufshcd_state != UFSHCD_STATE_ERROR) hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL; spin_unlock_irqrestore(hba->host->host_lock, flags); @@ -5581,10 +5662,17 @@ static void ufshcd_err_handler(struct work_struct *work) } ufshcd_set_eh_in_progress(hba); spin_unlock_irqrestore(hba->host->host_lock, flags); - pm_runtime_get_sync(hba->dev); - ufshcd_hold(hba, false); - + ufshcd_err_handling_prepare(hba); spin_lock_irqsave(hba->host->host_lock, flags); + /* + * A full reset and restore might have happened after preparation + * is finished, double check whether we should stop. + */ + if (ufshcd_err_handling_should_stop(hba)) { + if (hba->ufshcd_state != UFSHCD_STATE_ERROR) + hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL; + goto out; + } hba->ufshcd_state = UFSHCD_STATE_RESET; /* Complete requests that have door-bell cleared by h/w */ @@ -5662,10 +5750,12 @@ skip_pending_xfer_clear: hba->force_reset = false; spin_unlock_irqrestore(hba->host->host_lock, flags); err = ufshcd_reset_and_restore(hba); - spin_lock_irqsave(hba->host->host_lock, flags); if (err) dev_err(hba->dev, "%s: reset and restore failed with err %d\n", __func__, err); + else + ufshcd_recover_pm_error(hba); + spin_lock_irqsave(hba->host->host_lock, flags); } skip_err_handling: @@ -5677,11 +5767,11 @@ skip_err_handling: __func__, hba->saved_err, hba->saved_uic_err); } +out: ufshcd_clear_eh_in_progress(hba); spin_unlock_irqrestore(hba->host->host_lock, flags); ufshcd_scsi_unblock_requests(hba); - ufshcd_release(hba); - pm_runtime_put_sync(hba->dev); + ufshcd_err_handling_unprepare(hba); } /** -- 2.7.4