From 11c37c8b64b9d9d4ab19d387e6028eee3ec188d3 Mon Sep 17 00:00:00 2001 From: Neil Zhang Date: Tue, 10 Jul 2012 10:07:07 +0800 Subject: [PATCH] usb: gadget: mv_udc: fix boot up hang Fix boot up hang when enable udc without otg enabled. The root cause is that the clock will be shut down when probe routine is finished because of clock gating. When a gadget driver is registered at this time, it will call mv_udc_start which in turn will call mv_udc_vbus_session. If there is no cable attached at the boot up time, the vbus is low, so it will call stop_activity path without clock enabled which will cause system hang then. Actually, we need't go this path when clock is disabled, what we need to do is just jump out. Signed-off-by: Neil Zhang Signed-off-by: Felipe Balbi --- drivers/usb/gadget/mv_udc_core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/usb/gadget/mv_udc_core.c b/drivers/usb/gadget/mv_udc_core.c index 58edff9abcef..ad91de4d60d8 100644 --- a/drivers/usb/gadget/mv_udc_core.c +++ b/drivers/usb/gadget/mv_udc_core.c @@ -1221,12 +1221,16 @@ static int mv_udc_vbus_session(struct usb_gadget *gadget, int is_active) udc_start(udc); } } else if (udc->driver && udc->softconnect) { + if (!udc->active) + goto out; + /* stop all the transfer in queue*/ stop_activity(udc, udc->driver); udc_stop(udc); mv_udc_disable(udc); } +out: spin_unlock_irqrestore(&udc->lock, flags); return retval; } -- 2.39.5