[PATCH] usb: musb: only restore devctl when session was set in backup

[PATCH] usb: musb: only restore devctl when session was set in backup

[Bin Liu]

If the session bit was not set in the backup of devctl register,
restoring devctl would clear the session bit. Therefor, only restore
devctl register when the session bit was set in the backup.

This solves the device enumeration failure in otg mode exposed by commit
56f487c (PM / Runtime: Update last_busy in rpm_resume).

Fixes: 56f487c (PM / Runtime: Update last_busy in rpm_resume)

Cc: <stable@vger.kernel.org>
Signed-off-by: Bin Liu <b-liu@ti.com>
---
 drivers/usb/musb/musb_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 0286a39..f824336 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2418,7 +2418,8 @@ static void musb_restore_context(struct musb *musb)
 	musb_writew(musb_base, MUSB_INTRTXE, musb->intrtxe);
 	musb_writew(musb_base, MUSB_INTRRXE, musb->intrrxe);
 	musb_writeb(musb_base, MUSB_INTRUSBE, musb->context.intrusbe);
-	musb_writeb(musb_base, MUSB_DEVCTL, musb->context.devctl);
+	if (musb->context.devctl & MUSB_DEVCTL_SESSION)
+		musb_writeb(musb_base, MUSB_DEVCTL, musb->context.devctl);
 
 	for (i = 0; i < musb->config->num_eps; ++i) {
 		struct musb_hw_ep	*hw_ep;
-- 
1.9.1

[PATCH v2] usb: musb: only restore devctl when session was set in backup

[Bin Liu]

If the session bit was not set in the backup of devctl register,
restoring devctl would clear the session bit. Therefor, only restore
devctl register when the session bit was set in the backup.

This solves the device enumeration failure in otg mode exposed by commit
56f487c (PM / Runtime: Update last_busy in rpm_resume).

Cc: <stable@vger.kernel.org> # v4.2+
Signed-off-by: Bin Liu <b-liu@ti.com>
---
v2: revise cc stable@ with version and drop Fixes tag since it is not accurate.

 drivers/usb/musb/musb_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 0286a39..f824336 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2418,7 +2418,8 @@ static void musb_restore_context(struct musb *musb)
 	musb_writew(musb_base, MUSB_INTRTXE, musb->intrtxe);
 	musb_writew(musb_base, MUSB_INTRRXE, musb->intrrxe);
 	musb_writeb(musb_base, MUSB_INTRUSBE, musb->context.intrusbe);
-	musb_writeb(musb_base, MUSB_DEVCTL, musb->context.devctl);
+	if (musb->context.devctl & MUSB_DEVCTL_SESSION)
+		musb_writeb(musb_base, MUSB_DEVCTL, musb->context.devctl);
 
 	for (i = 0; i < musb->config->num_eps; ++i) {
 		struct musb_hw_ep	*hw_ep;
-- 
1.9.1