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From:   Can Guo <cang@codeaurora.org>
To:     asutoshd@codeaurora.org, nguyenb@codeaurora.org,
        hongwus@codeaurora.org, ziqichen@codeaurora.org,
        linux-scsi@vger.kernel.org, kernel-team@android.com,
        cang@codeaurora.org
Cc:     Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Stanley Chu <stanley.chu@mediatek.com>,
        Bean Huo <beanhuo@micron.com>,
        Jaegeuk Kim <jaegeuk@kernel.org>,
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v3 5/9] scsi: ufs: Simplify error handling preparation
Date:   Wed,  9 Jun 2021 21:43:33 -0700
Message-Id: <1623300218-9454-6-git-send-email-cang@codeaurora.org>
In-Reply-To: <1623300218-9454-1-git-send-email-cang@codeaurora.org>
References: <1623300218-9454-1-git-send-email-cang@codeaurora.org>
Precedence: bulk

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@codeaurora.org>
---
 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;
 }
-- 
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