[PATCH 4.9 108/152] scsi: ufs: issue link starup 2 times if device isnt active

From: Greg Kroah-Hartman
Date: Mon Apr 10 2017 - 13:29:15 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: "subhashj@xxxxxxxxxxxxxx" <subhashj@xxxxxxxxxxxxxx>

[ Upstream commit 7caf489b99a42a9017ef3d733912aea8794677e7 ]

If we issue the link startup to the device while its UniPro state is
LinkDown (and device state is sleep/power-down) then link startup
will not move the device state to Active. Device will only move to
active state if the link starup is issued when its UniPro state is
LinkUp. So in this case, we would have to issue the link startup 2
times to make sure that device moves to active state.

Reviewed-by: Gilad Broner <gbroner@xxxxxxxxxxxxxx>
Signed-off-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)

--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3130,7 +3130,16 @@ static int ufshcd_link_startup(struct uf
{
int ret;
int retries = DME_LINKSTARTUP_RETRIES;
+ bool link_startup_again = false;

+ /*
+ * If UFS device isn't active then we will have to issue link startup
+ * 2 times to make sure the device state move to active.
+ */
+ if (!ufshcd_is_ufs_dev_active(hba))
+ link_startup_again = true;
+
+link_startup:
do {
ufshcd_vops_link_startup_notify(hba, PRE_CHANGE);

@@ -3156,6 +3165,12 @@ static int ufshcd_link_startup(struct uf
/* failed to get the link up... retire */
goto out;

+ if (link_startup_again) {
+ link_startup_again = false;
+ retries = DME_LINKSTARTUP_RETRIES;
+ goto link_startup;
+ }
+
if (hba->quirks & UFSHCD_QUIRK_BROKEN_LCC) {
ret = ufshcd_disable_device_tx_lcc(hba);
if (ret)
@@ -6630,10 +6645,12 @@ int ufshcd_init(struct ufs_hba *hba, voi
pm_runtime_get_sync(dev);

/*
- * The device-initialize-sequence hasn't been invoked yet.
- * Set the device to power-off state
+ * We are assuming that device wasn't put in sleep/power-down
+ * state exclusively during the boot stage before kernel.
+ * This assumption helps avoid doing link startup twice during
+ * ufshcd_probe_hba().
*/
- ufshcd_set_ufs_dev_poweroff(hba);
+ ufshcd_set_ufs_dev_active(hba);

async_schedule(ufshcd_async_scan, hba);