On 2019-10-31 22:44, Mark Salyzyn wrote:
On 10/22/19 9:13 PM, Can Guo wrote:
Some UFS host controllers need their specific implementations of
resetting
to get them into a good state. Provide a new vops to allow the
platform
driver to implement this own reset operation.
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 16 ++++++++++++++++
drivers/scsi/ufs/ufshcd.h | 10 ++++++++++
2 files changed, 26 insertions(+)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c28c144..161e3c4 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3859,6 +3859,14 @@ static int ufshcd_link_recovery(struct ufs_hba
*hba)
ufshcd_set_eh_in_progress(hba);
spin_unlock_irqrestore(hba->host->host_lock, flags);
+ ret = ufshcd_vops_full_reset(hba);
+ if (ret)
+ dev_warn(hba->dev, "%s: full reset returned %d\n",
+ __func__, ret);
+
+ /* Reset the attached device */
+ ufshcd_vops_device_reset(hba);
+
ret = ufshcd_host_reset_and_restore(hba);
spin_lock_irqsave(hba->host->host_lock, flags);
In all your cases, especially after this adjustment,
ufshcd_vops_full_reset is called blindly (+error checking message)
before ufshcd_vops_device_reset. What about dropping the .full_reset
(should really have been called .hw_reset or .host_reset) addition to
the vops, just adding ufshcd_vops_device_reset call here before
ufshcd_host_reset_and_restore, and in the driver folding the
ufshcd_vops_full_reset code into the .device_reset handler?
Would that be workable? It would be simpler if so.
I can see a desire for the heads up
(ufshcd_vops_full_reset+)ufshcd_vops_device_reset calls before
ufshcd_host_reset_and_restore because that function will spin 10
seconds waiting for a response from a standardized register, that
itself could be hardware locked up requiring product specific reset
procedures. But if that is the case, then what about all the other
calls to ufshcd_host_reset_and_restore in this file that are not
provided the heads up? My guess is that the host device only
demonstrated issues in the ufshcd_link_recovery handling path? Are you
sure this is the only path that tickles the controller into a hardware
lockup state?
Sincerely -- Mark Salyzyn
Hi Mark Salyzyn,
Folding the "full_reset" vops inito "device_reset" vops is one choice
for now. Shall do that.
Your guess is correct. the head up is needed in ufshcd_link_recovery()
path because
link is already in bad state when we are here, expeically after hibern8
exit fails.
So we need a full reset to PHY and host controller here before
host_reset_and_restore.
But other calls to host_reset_and_restore are under good conditions.
Regards,
Can Guo.
