From d5d1e1bed4da02bd7a2352ab495721e31a7d95e4 Mon Sep 17 00:00:00 2001 From: Peter Chen Date: Wed, 11 Feb 2015 12:44:41 +0800 Subject: [PATCH] usb: chipidea: udc: return immediately if re-enable non-empty endpoint Some gadget driver (like uac1) will try to enable endpoint again even the ep is not empty, it will cause the ep reset again and may affect the dTD list which has already queued. It returns -EBUSY immediately, and indicate the endpoint is in use. In this way, the ep's behavior will not be affected, and the gadget driver is also notified. Cc: Xuebing Wang Signed-off-by: Peter Chen Signed-off-by: Greg Kroah-Hartman --- drivers/usb/chipidea/udc.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c index ff45104..5244542 100644 --- a/drivers/usb/chipidea/udc.c +++ b/drivers/usb/chipidea/udc.c @@ -1151,10 +1151,13 @@ static int ep_enable(struct usb_ep *ep, /* only internal SW should enable ctrl endpts */ - hwep->ep.desc = desc; - - if (!list_empty(&hwep->qh.queue)) + if (!list_empty(&hwep->qh.queue)) { dev_warn(hwep->ci->dev, "enabling a non-empty endpoint!\n"); + spin_unlock_irqrestore(hwep->lock, flags); + return -EBUSY; + } + + hwep->ep.desc = desc; hwep->dir = usb_endpoint_dir_in(desc) ? TX : RX; hwep->num = usb_endpoint_num(desc); -- 2.7.4