usb: gadget: uvc: fix error path in uvc_function_bind()

The "video->minor = -1" assigment is done in V4L2 by
video_register_device() so it is removed here.
Now. uvc_function_bind() calls in error case uvc_function_unbind() for
cleanup. The problem is that uvc_function_unbind() frees the uvc struct
and uvc_bind_config() does as well in error case of usb_add_function().
Removing kfree() in usb_add_function() would make the patch smaller but
it would look odd because the new allocated memory is not cleaned up.
However it is not guaranteed that if we call usb_add_function() we also
get to the bind function.
Therefore the patch extracts the conditional cleanup from
uvc_function_unbind() applies to uvc_function_bind().
uvc_function_unbind() now contains only the complete cleanup which is
required once everything has been registrated.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Bhupesh Sharma <bhupesh.sharma@st.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/gadget/f_uvc.c b/drivers/usb/gadget/f_uvc.c
index 2a8bf06..10f13c1 100644 (file)
--- a/drivers/usb/gadget/f_uvc.c
+++ b/drivers/usb/gadget/f_uvc.c
@@ -417,7 +417,6 @@ uvc_register_video(struct uvc_device *uvc)
                return -ENOMEM;
 
        video->parent = &cdev->gadget->dev;
-       video->minor = -1;
        video->fops = &uvc_v4l2_fops;
        video->release = video_device_release;
        strncpy(video->name, cdev->gadget->name, sizeof(video->name));
@@ -577,23 +576,12 @@ uvc_function_unbind(struct usb_configuration *c, struct usb_function *f)
 
        INFO(cdev, "uvc_function_unbind\n");
 
-       if (uvc->vdev) {
-               if (uvc->vdev->minor == -1)
-                       video_device_release(uvc->vdev);
-               else
-                       video_unregister_device(uvc->vdev);
-               uvc->vdev = NULL;
-       }
-
-       if (uvc->control_ep)
-               uvc->control_ep->driver_data = NULL;
-       if (uvc->video.ep)
-               uvc->video.ep->driver_data = NULL;
+       video_unregister_device(uvc->vdev);
+       uvc->control_ep->driver_data = NULL;
+       uvc->video.ep->driver_data = NULL;
 
-       if (uvc->control_req) {
-               usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
-               kfree(uvc->control_buf);
-       }
+       usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
+       kfree(uvc->control_buf);
 
        kfree(f->descriptors);
        kfree(f->hs_descriptors);
@@ -740,7 +728,22 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
        return 0;
 
 error:
-       uvc_function_unbind(c, f);
+       if (uvc->vdev)
+               video_device_release(uvc->vdev);
+
+       if (uvc->control_ep)
+               uvc->control_ep->driver_data = NULL;
+       if (uvc->video.ep)
+               uvc->video.ep->driver_data = NULL;
+
+       if (uvc->control_req) {
+               usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
+               kfree(uvc->control_buf);
+       }
+
+       kfree(f->descriptors);
+       kfree(f->hs_descriptors);
+       kfree(f->ss_descriptors);
        return ret;
 }