@@ -888,13 +888,37 @@ static void uvc_function_unbind(struct u
{
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);
@@ -913,6 +937,7 @@ static struct usb_function *uvc_alloc(st
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);
@@ -14,6 +14,7 @@
#include <linux/spinlock.h>
#include <linux/usb/composite.h>
#include <linux/videodev2.h>
+#include <linux/wait.h>
#include <media/v4l2-device.h>
#include <media/v4l2-dev.h>
@@ -118,6 +119,7 @@ struct uvc_device {
struct usb_function func;
struct uvc_video video;
bool func_connected;
+ wait_queue_head_t func_connected_queue;
/* Descriptors */
struct {
@@ -252,10 +252,11 @@ uvc_v4l2_subscribe_event(struct v4l2_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