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From: Can Guo <cang@codeaurora.org>
To: asutoshd@codeaurora.org, nguyenb@codeaurora.org,
	rnayak@codeaurora.org, linux-scsi@vger.kernel.org,
	kernel-team@android.com, saravanak@google.com,
	salyzyn@google.com, cang@codeaurora.org
Cc: Subhash Jadavani <subhashj@codeaurora.org>,
	Alim Akhtar <alim.akhtar@samsung.com>,
	Avri Altman <avri.altman@wdc.com>,
	Pedro Sousa <pedrom.sousa@synopsys.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>,
	Tomas Winkler <tomas.winkler@intel.com>,
	Venkat Gopalakrishnan <venkatg@codeaurora.org>,
	linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v5 7/7] scsi: ufs: Fix error handing during hibern8 enter
Date: Thu, 14 Nov 2019 22:09:30 -0800
Message-ID: <1573798172-20534-8-git-send-email-cang@codeaurora.org> (raw)
In-Reply-To: <1573798172-20534-1-git-send-email-cang@codeaurora.org>

From: Subhash Jadavani <subhashj@codeaurora.org>

During clock gating (ufshcd_gate_work()), we first put the link hibern8 by
calling ufshcd_uic_hibern8_enter() and if ufshcd_uic_hibern8_enter()
returns success (0) then we gate all the clocks.
Now let’s zoom in to what ufshcd_uic_hibern8_enter() does internally:
It calls __ufshcd_uic_hibern8_enter() and if failure is encountered,
link recovery shall put the link back to the highest HS gear and
returns success (0) to ufshcd_uic_hibern8_enter() which is the issue as
link is still in active state due to recovery!
Now ufshcd_uic_hibern8_enter() returns success to ufshcd_gate_work() and
hence it goes ahead with gating the UFS clock while link is still in active
state hence I believe controller would raise UIC error interrupts. But when
we service the interrupt, clocks might have already been disabled!

This change fixes for this by returning failure from
__ufshcd_uic_hibern8_enter() if recovery succeeds as link is still not in
hibern8, upon receiving the error ufshcd_hibern8_enter() would initiate
retry to put the link state back into hibern8.

Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
---
 drivers/scsi/ufs/ufshcd.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index d662641..e1ee961 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3891,15 +3891,24 @@ static int __ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
 			     ktime_to_us(ktime_sub(ktime_get(), start)), ret);
 
 	if (ret) {
+		int err;
+
 		dev_err(hba->dev, "%s: hibern8 enter failed. ret = %d\n",
 			__func__, ret);
 
 		/*
-		 * If link recovery fails then return error so that caller
-		 * don't retry the hibern8 enter again.
+		 * If link recovery fails then return error code returned from
+		 * ufshcd_link_recovery().
+		 * If link recovery succeeds then return -EAGAIN to attempt
+		 * hibern8 enter retry again.
 		 */
-		if (ufshcd_link_recovery(hba))
-			ret = -ENOLINK;
+		err = ufshcd_link_recovery(hba);
+		if (err) {
+			dev_err(hba->dev, "%s: link recovery failed", __func__);
+			ret = err;
+		} else {
+			ret = -EAGAIN;
+		}
 	} else
 		ufshcd_vops_hibern8_notify(hba, UIC_CMD_DME_HIBER_ENTER,
 								POST_CHANGE);
@@ -3913,7 +3922,7 @@ static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
 
 	for (retries = UIC_HIBERN8_ENTER_RETRIES; retries > 0; retries--) {
 		ret = __ufshcd_uic_hibern8_enter(hba);
-		if (!ret || ret == -ENOLINK)
+		if (!ret)
 			goto out;
 	}
 out:
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


  parent reply index

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-15  6:09 [PATCH v5 0/7] UFS driver general fixes bundle 3 Can Guo
2019-11-15  6:09 ` [PATCH v5 1/7] scsi: ufs: Add device reset in link recovery path Can Guo
2019-11-15  6:25   ` Stanley Chu
2019-11-15  6:09 ` [PATCH v5 2/7] scsi: ufs-qcom: Add reset control support for host controller Can Guo
2019-11-15 10:08   ` Avri Altman
2019-12-16 19:04   ` Vinod Koul
2019-12-16 19:12     ` Jeffrey Hugo
2019-12-17  0:37       ` cang
2019-12-17  4:13         ` Vinod Koul
2019-12-17  7:10           ` cang
2019-12-17  9:24             ` Vinod Koul
2019-12-17 10:09               ` cang
2019-12-17 15:08                 ` Vinod Koul
2019-12-17 16:00                   ` Jeffrey Hugo
2019-12-17 18:44                     ` cang
2019-12-18  4:12                       ` Vinod Koul
2019-12-19  7:12                         ` cang
2019-12-19 14:21                           ` Vinod Koul
2019-12-19 14:25                             ` Jeffrey Hugo
2019-12-19 14:52                               ` Vinod Koul
2019-12-20  0:30                                 ` cang
2019-11-15  6:09 ` [PATCH v5 3/7] scsi: ufs: Fix up auto hibern8 enablement Can Guo
2019-11-15  6:35   ` Stanley Chu
2019-11-15  7:03     ` Can Guo
2019-11-15  7:18       ` Stanley Chu
2019-11-15 12:27         ` Can Guo
2019-11-15 13:46           ` Stanley Chu
2019-11-15  6:09 ` [PATCH v5 4/7] scsi: ufs: Fix register dump caused sleep in atomic context Can Guo
2019-11-15  6:09 ` [PATCH v5 5/7] scsi: ufs: Fix irq return code Can Guo
2019-11-15  6:09 ` [PATCH v5 6/7] scsi: ufs: Abort gating if clock on request is pending Can Guo
2019-11-15  6:09 ` Can Guo [this message]
2019-11-15 10:12   ` [PATCH v5 7/7] scsi: ufs: Fix error handing during hibern8 enter Avri Altman
2019-11-17 16:36   ` [EXT] " Bean Huo (beanhuo)
2019-11-19  4:28 ` [PATCH v5 0/7] UFS driver general fixes bundle 3 Martin K. Petersen

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