[PATCH v4 07/10] scsi: ufs: Simplify error handling preparation

From: Can Guo
Date: Wed Jun 23 2021 - 03:37:45 EST


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.

Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 56 +++++++++++++++++++++++++----------------------
1 file changed, 30 insertions(+), 26 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index a09e4a2..379c6a0 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
@@ -5905,34 +5905,31 @@ 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)
{
/*
* It is not safe to perform error handling while suspend or resume is
* in progress. Hence the lock_system_sleep() call.
*/
lock_system_sleep();
+ /*
+ * Exclusively call pm_runtime_get_sync(hba->dev) once, in case
+ * following ufshcd_rpm_get_sync() fails.
+ */
+ pm_runtime_get_sync(hba->dev);
+ if (pm_runtime_suspended(hba->dev) || hba->is_sys_suspended) {
+ pm_runtime_put(hba->dev);
+ unlock_system_sleep();
+ 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_wlu_sys_suspended) {
- enum ufs_pm_op pm_op;
+ enum ufs_pm_op pm_op = hba->is_wlu_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_wlu_sys_suspended ? UFS_SYSTEM_PM : UFS_RUNTIME_PM;
ufshcd_vops_resume(hba, pm_op);
} else {
ufshcd_hold(hba, false);
@@ -5946,16 +5943,19 @@ 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);
unlock_system_sleep();
}

@@ -6048,9 +6048,13 @@ 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);
@@ -6194,7 +6198,6 @@ 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);
@@ -8995,6 +8998,9 @@ 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:
@@ -9004,8 +9010,6 @@ 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->wlu_pm_op_in_progress = false;
return ret <= 0 ? ret : -EINVAL;
}
--
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