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); diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h index 9d5f17b551bb..0966c5aa2492 100644 --- a/drivers/usb/gadget/function/uvc.h +++ b/drivers/usb/gadget/function/uvc.h @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -127,6 +128,7 @@ struct uvc_device { struct usb_function func; struct uvc_video video; bool func_connected; + wait_queue_head_t func_connected_queue; /* Descriptors */ struct { diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c index 197c26f7aec6..65abd55ce234 100644 --- a/drivers/usb/gadget/function/uvc_v4l2.c +++ b/drivers/usb/gadget/function/uvc_v4l2.c @@ -252,10 +252,11 @@ uvc_v4l2_subscribe_event(struct v4l2_fh *fh, static void uvc_v4l2_disable(struct uvc_device *uvc) { - uvc->func_connected = false; uvc_function_disconnect(uvc); uvcg_video_enable(&uvc->video, 0); uvcg_free_buffers(&uvc->video.queue); + uvc->func_connected = false; + wake_up_interruptible(&uvc->func_connected_queue); } static int