[PATCH 163/270] usb: dwc3: gadget: fix 'endpoint always busy' bug

Herton Ronaldo Krzesinski herton.krzesinski at canonical.com
Mon Nov 26 16:57:33 UTC 2012

3.5.7u1 -stable review patch.  If anyone has any objections, please let me know.


From: Felipe Balbi <balbi at ti.com>

commit 041d81f493d90c940ec41f0ec98bc7c4f2fba431 upstream.

If a USB transfer has already been started, meaning
we have already issued StartTransfer command to that
particular endpoint, DWC3_EP_BUSY flag has also
already been set.

When we try to cancel this transfer which is already
in controller's cache, we will not receive XferComplete
event and we must clear DWC3_EP_BUSY in order to allow
subsequent requests to be properly started.

The best place to clear that flag is right after issuing

Reported-by: Moiz Sonasath <m-sonasath at ti.com>
Signed-off-by: Felipe Balbi <balbi at ti.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
 drivers/usb/dwc3/gadget.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 0b24d9d..c7721db 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1832,6 +1832,7 @@ static void dwc3_stop_active_transfer(struct dwc3 *dwc, u32 epnum)
 		ret = dwc3_send_gadget_ep_cmd(dwc, dep->number, cmd, &params);
 		dep->res_trans_idx = 0;
+		dep->flags &= ~DWC3_EP_BUSY;

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