[PATCH 4.9 11/60] usb: musb: dsps: keep VBUS on for host-only mode

[Greg Kroah-Hartman]

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

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

From: Bin Liu <b-liu@xxxxxx>

commit b3addcf0d1f04f53fcc302577d5a5e964c18531a upstream.

Currently VBUS is turned off while a usb device is detached, and turned
on again by the polling routine. This short period VBUS loss prevents
usb modem to switch mode.

VBUS should be constantly on for host-only mode, so this changes the
driver to not turn off VBUS for host-only mode.

Fixes: 2f3fd2c5bde1 ("usb: musb: Prepare dsps glue layer for PM runtime support")
Reported-by: Moreno Bartalucci <moreno.bartalucci@xxxxxxxxxxxx>
Acked-by: Tony Lindgren <tony@xxxxxxxxxxx>
Signed-off-by: Bin Liu <b-liu@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/musb/musb_dsps.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/usb/musb/musb_dsps.c
+++ b/drivers/usb/musb/musb_dsps.c
@@ -213,6 +213,12 @@ static int dsps_check_status(struct musb
 				msecs_to_jiffies(wrp->poll_timeout));
 		break;
 	case OTG_STATE_A_WAIT_BCON:
+		/* keep VBUS on for host-only mode */
+		if (musb->port_mode == MUSB_PORT_MODE_HOST) {
+			mod_timer(&glue->timer, jiffies +
+					msecs_to_jiffies(wrp->poll_timeout));
+			break;
+		}
 		musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
 		skip_session = 1;
 		/* fall */