From: Jaegeuk Kim <jaegeuk@kernel.org>
Date: Thu, 7 Jan 2021 18:53:15 +0000 (-0800)
Subject: scsi: ufs: Fix livelock of ufshcd_clear_ua_wluns()
X-Git-Tag: v5.15~1808^2~11
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4ee7ee530bc2bae6268247988d86722c65d02a37;p=platform%2Fkernel%2Flinux-starfive.git

scsi: ufs: Fix livelock of ufshcd_clear_ua_wluns()

When gate_work/ungate_work experience an error during hibern8_enter or exit
we can livelock:

 ufshcd_err_handler()
   ufshcd_scsi_block_requests()
   ufshcd_reset_and_restore()
     ufshcd_clear_ua_wluns() -> stuck
   ufshcd_scsi_unblock_requests()

In order to avoid this, ufshcd_clear_ua_wluns() can be called per recovery
flows such as suspend/resume, link_recovery, and error_handler.

Link: https://lore.kernel.org/r/20210107185316.788815-2-jaegeuk@kernel.org
Fixes: 1918651f2d7e ("scsi: ufs: Clear UAC for RPMB after ufshcd resets")
Reviewed-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index e31d2c5..cff4f52 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3996,6 +3996,8 @@ int ufshcd_link_recovery(struct ufs_hba *hba)
 	if (ret)
 		dev_err(hba->dev, "%s: link recovery failed, err %d",
 			__func__, ret);
+	else
+		ufshcd_clear_ua_wluns(hba);
 
 	return ret;
 }
@@ -6001,6 +6003,9 @@ skip_err_handling:
 	ufshcd_scsi_unblock_requests(hba);
 	ufshcd_err_handling_unprepare(hba);
 	up(&hba->eh_sem);
+
+	if (!err && needs_reset)
+		ufshcd_clear_ua_wluns(hba);
 }
 
 /**
@@ -6938,14 +6943,11 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
 	ufshcd_set_clk_freq(hba, true);
 
 	err = ufshcd_hba_enable(hba);
-	if (err)
-		goto out;
 
 	/* Establish the link again and restore the device */
-	err = ufshcd_probe_hba(hba, false);
 	if (!err)
-		ufshcd_clear_ua_wluns(hba);
-out:
+		err = ufshcd_probe_hba(hba, false);
+
 	if (err)
 		dev_err(hba->dev, "%s: Host init failed %d\n", __func__, err);
 	ufshcd_update_evt_hist(hba, UFS_EVT_HOST_RESET, (u32)err);
@@ -7716,6 +7718,8 @@ static int ufshcd_add_lus(struct ufs_hba *hba)
 	if (ret)
 		goto out;
 
+	ufshcd_clear_ua_wluns(hba);
+
 	/* Initialize devfreq after UFS device is detected */
 	if (ufshcd_is_clkscaling_supported(hba)) {
 		memcpy(&hba->clk_scaling.saved_pwr_info.info,
@@ -7917,8 +7921,6 @@ out:
 		pm_runtime_put_sync(hba->dev);
 		ufshcd_exit_clk_scaling(hba);
 		ufshcd_hba_exit(hba);
-	} else {
-		ufshcd_clear_ua_wluns(hba);
 	}
 }
 
@@ -8775,6 +8777,7 @@ enable_gating:
 		ufshcd_resume_clkscaling(hba);
 	hba->clk_gating.is_suspended = false;
 	hba->dev_info.b_rpm_dev_flush_capable = false;
+	ufshcd_clear_ua_wluns(hba);
 	ufshcd_release(hba);
 out:
 	if (hba->dev_info.b_rpm_dev_flush_capable) {
@@ -8885,6 +8888,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);
 	}
 
+	ufshcd_clear_ua_wluns(hba);
+
 	/* Schedule clock gating in case of no access to UFS device yet */
 	ufshcd_release(hba);