On 2019-11-14 19:06, Avri Altman wrote:
From: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
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() which on detecting the
LINERESET,
initiates the full recovery and puts the link back to 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@xxxxxxxxxxxxxx>
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
---
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
7a5a904..934c27a 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
(-ENOLINK)
+ * returned ufshcd_link_recovery().
+ * If link recovery succeeds then return -EAGAIN to
attempt
+ * hibern8 enter retry again.
You no longer returning -ENOLINK, and either way retrying, regardless
of the error code.
Better check that the commit log is still telling the correct story,
taking into consideration all those recent fixes and all.
Thanks for pointing this.
Best Regards,
Can Guo.
*/
- 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
