| Message ID | 20210901124650.31653-1-caihuoqing@baidu.com |
|---|---|
| State | Accepted |
| Commit | 538314dbfc8adbe8af64a13c9f14e907a0a887fb |
| Headers | show |
| Series | [v3] usb: stkwebcam: Update the reference count of the usb device structure | expand |
Hello, +Cc Hans Verkuil <hverkuil@xs4all.nl> Cai > Subject: [PATCH v3] usb: stkwebcam: Update the reference count of the usb > device structure > > Use usb_get_dev() to increment the reference count of the usb device > structure in order to avoid releasing the structure while it is still in > use. And use usb_put_dev() to decrement the reference count and thus, > when it will be equal to 0 the structure will be released. > > Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> > --- > v2->v3: > *call usb_put_dev() in the error path of stk_camera_probe > *move v4l2_ctrl_handler_free/v4l2_device_unregister/kfree(dev) > from stk_camera_disconnect() to stk_v4l_dev_release() > > drivers/media/usb/stkwebcam/stk-webcam.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c > b/drivers/media/usb/stkwebcam/stk-webcam.c > index 0e231e576dc3..9f445e6ab5fa 100644 > --- a/drivers/media/usb/stkwebcam/stk-webcam.c > +++ b/drivers/media/usb/stkwebcam/stk-webcam.c > @@ -1234,6 +1234,11 @@ static void stk_v4l_dev_release(struct > video_device *vd) > if (dev->sio_bufs != NULL || dev->isobufs != NULL) > pr_err("We are leaking memory\n"); > usb_put_intf(dev->interface); > + usb_put_dev(dev->udev); > + > + v4l2_ctrl_handler_free(&dev->hdl); > + v4l2_device_unregister(&dev->v4l2_dev); > + kfree(dev); > } > > static const struct video_device stk_v4l_data = { > @@ -1309,7 +1314,7 @@ static int stk_camera_probe(struct usb_interface > *interface, > init_waitqueue_head(&dev->wait_frame); > dev->first_init = 1; /* webcam LED management */ > > - dev->udev = udev; > + dev->udev = usb_get_dev(udev); > dev->interface = interface; > usb_get_intf(interface); > > @@ -1365,6 +1370,7 @@ static int stk_camera_probe(struct usb_interface > *interface, > > error_put: > usb_put_intf(interface); > + usb_put_dev(dev->udev); > error: > v4l2_ctrl_handler_free(hdl); > v4l2_device_unregister(&dev->v4l2_dev); > @@ -1385,9 +1391,6 @@ static void stk_camera_disconnect(struct > usb_interface *interface) > video_device_node_name(&dev->vdev)); > > video_unregister_device(&dev->vdev); > - v4l2_ctrl_handler_free(&dev->hdl); > - v4l2_device_unregister(&dev->v4l2_dev); > - kfree(dev); > } > > #ifdef CONFIG_PM > -- > 2.25.1
diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c b/drivers/media/usb/stkwebcam/stk-webcam.c index 0e231e576dc3..9f445e6ab5fa 100644 --- a/drivers/media/usb/stkwebcam/stk-webcam.c +++ b/drivers/media/usb/stkwebcam/stk-webcam.c @@ -1234,6 +1234,11 @@ static void stk_v4l_dev_release(struct video_device *vd) if (dev->sio_bufs != NULL || dev->isobufs != NULL) pr_err("We are leaking memory\n"); usb_put_intf(dev->interface); + usb_put_dev(dev->udev); + + v4l2_ctrl_handler_free(&dev->hdl); + v4l2_device_unregister(&dev->v4l2_dev); + kfree(dev); } static const struct video_device stk_v4l_data = { @@ -1309,7 +1314,7 @@ static int stk_camera_probe(struct usb_interface *interface, init_waitqueue_head(&dev->wait_frame); dev->first_init = 1; /* webcam LED management */ - dev->udev = udev; + dev->udev = usb_get_dev(udev); dev->interface = interface; usb_get_intf(interface); @@ -1365,6 +1370,7 @@ static int stk_camera_probe(struct usb_interface *interface, error_put: usb_put_intf(interface); + usb_put_dev(dev->udev); error: v4l2_ctrl_handler_free(hdl); v4l2_device_unregister(&dev->v4l2_dev); @@ -1385,9 +1391,6 @@ static void stk_camera_disconnect(struct usb_interface *interface) video_device_node_name(&dev->vdev)); video_unregister_device(&dev->vdev); - v4l2_ctrl_handler_free(&dev->hdl); - v4l2_device_unregister(&dev->v4l2_dev); - kfree(dev); } #ifdef CONFIG_PM
Use usb_get_dev() to increment the reference count of the usb device structure in order to avoid releasing the structure while it is still in use. And use usb_put_dev() to decrement the reference count and thus, when it will be equal to 0 the structure will be released. Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> --- v2->v3: *call usb_put_dev() in the error path of stk_camera_probe *move v4l2_ctrl_handler_free/v4l2_device_unregister/kfree(dev) from stk_camera_disconnect() to stk_v4l_dev_release() drivers/media/usb/stkwebcam/stk-webcam.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)