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path: root/drivers/usb/gadget/function/f_uvc.c
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Diffstat (limited to 'drivers/usb/gadget/function/f_uvc.c')
-rw-r--r--drivers/usb/gadget/function/f_uvc.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index e6de56afec6e..bf0a3fc2d776 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -889,13 +889,37 @@ static void uvc_function_unbind(struct usb_configuration *c,
{
struct usb_composite_dev *cdev = c->cdev;
struct uvc_device *uvc = to_uvc(f);
+ long wait_ret = 1;
uvcg_info(f, "%s()\n", __func__);
+ /* If we know we're connected via v4l2, then there should be a cleanup
+ * of the device from userspace either via UVC_EVENT_DISCONNECT or
+ * though the video device removal uevent. Allow some time for the
+ * application to close out before things get deleted.
+ */
+ if (uvc->func_connected) {
+ uvcg_dbg(f, "waiting for clean disconnect\n");
+ wait_ret = wait_event_interruptible_timeout(uvc->func_connected_queue,
+ uvc->func_connected == false, msecs_to_jiffies(500));
+ uvcg_dbg(f, "done waiting with ret: %ld\n", wait_ret);
+ }
+
device_remove_file(&uvc->vdev.dev, &dev_attr_function_name);
video_unregister_device(&uvc->vdev);
v4l2_device_unregister(&uvc->v4l2_dev);
+ if (uvc->func_connected) {
+ /* Wait for the release to occur to ensure there are no longer any
+ * pending operations that may cause panics when resources are cleaned
+ * up.
+ */
+ uvcg_warn(f, "%s no clean disconnect, wait for release\n", __func__);
+ wait_ret = wait_event_interruptible_timeout(uvc->func_connected_queue,
+ uvc->func_connected == false, msecs_to_jiffies(1000));
+ uvcg_dbg(f, "done waiting for release with ret: %ld\n", wait_ret);
+ }
+
usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
kfree(uvc->control_buf);
@@ -914,6 +938,7 @@ static struct usb_function *uvc_alloc(struct usb_function_instance *fi)
mutex_init(&uvc->video.mutex);
uvc->state = UVC_STATE_DISCONNECTED;
+ init_waitqueue_head(&uvc->func_connected_queue);
opts = fi_to_f_uvc_opts(fi);
mutex_lock(&opts->lock);