[PATCH] usb: gadget: uvc_video: unlock before submitting a request to ep

From: Piyush Mehta
Date: Thu Nov 02 2023 - 03:12:10 EST


There could be chances where the usb_ep_queue() could fail and trigger
complete() handler with error status. In this case, if usb_ep_queue()
is called with lock held and the triggered complete() handler is waiting
for the same lock to be cleared could result in a deadlock situation and
could result in system hang. To aviod this scenerio, call usb_ep_queue()
with lock removed. This patch does the same.

Signed-off-by: Piyush Mehta <piyush.mehta@xxxxxxx>
---
drivers/usb/gadget/function/uvc_video.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index 91af3b1ef0d4..0a5d9ac145e7 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -460,11 +460,12 @@ static void uvcg_video_pump(struct work_struct *work)
req->no_interrupt = 1;
}

- /* Queue the USB request */
- ret = uvcg_video_ep_queue(video, req);
spin_unlock_irqrestore(&queue->irqlock, flags);

+ /* Queue the USB request */
+ ret = uvcg_video_ep_queue(video, req);
if (ret < 0) {
+ usb_ep_set_halt(video->ep);
uvcg_queue_cancel(queue, 0);
break;
}
--
2.25.1