patch "usb: musb: only restore devctl when session was set in backup" added to usb-linus

patch "usb: musb: only restore devctl when session was set in backup" added to usb-linus

[gregkh]

This is a note to let you know that I've just added the patch titled

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

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


>From 84ac5d1140f716a616522f952734e850448d2556 Mon Sep 17 00:00:00 2001
From: Bin Liu <b-liu@ti.com>
Date: Tue, 31 May 2016 10:05:24 -0500
Subject: usb: musb: only restore devctl when session was set in backup

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 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 0286a39ea01d..f824336def5c 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;
-- 
2.8.3