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Message-Id: <1573798172-20534-8-git-send-email-cang@codeaurora.org>
Date: Thu, 14 Nov 2019 22:09:30 -0800
From: Can Guo <cang@...eaurora.org>
To: asutoshd@...eaurora.org, nguyenb@...eaurora.org,
rnayak@...eaurora.org, linux-scsi@...r.kernel.org,
kernel-team@...roid.com, saravanak@...gle.com, salyzyn@...gle.com,
cang@...eaurora.org
Cc: Subhash Jadavani <subhashj@...eaurora.org>,
Alim Akhtar <alim.akhtar@...sung.com>,
Avri Altman <avri.altman@....com>,
Pedro Sousa <pedrom.sousa@...opsys.com>,
"James E.J. Bottomley" <jejb@...ux.ibm.com>,
"Martin K. Petersen" <martin.petersen@...cle.com>,
Stanley Chu <stanley.chu@...iatek.com>,
Bean Huo <beanhuo@...ron.com>,
Tomas Winkler <tomas.winkler@...el.com>,
Venkat Gopalakrishnan <venkatg@...eaurora.org>,
linux-kernel@...r.kernel.org (open list)
Subject: [PATCH v5 7/7] scsi: ufs: Fix error handing during hibern8 enter
From: Subhash Jadavani <subhashj@...eaurora.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@...eaurora.org>
Signed-off-by: Can Guo <cang@...eaurora.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:
--
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