This is a note to let you know that I've just added the patch titled
media: s2255: Use refcount_t instead of atomic_t for num_channels
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
media-s2255-use-refcount_t-instead-of-atomic_t-for-n.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 468d88b607867c35b6f644222220afe0ff9dd061
Author: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
Date: Mon Apr 29 16:04:50 2024 +0100
media: s2255: Use refcount_t instead of atomic_t for num_channels
[ Upstream commit 6cff72f6bcee89228a662435b7c47e21a391c8d0 ]
Use an API that resembles more the actual use of num_channels.
Found by cocci:
drivers/media/usb/s2255/s2255drv.c:2362:5-24: WARNING: atomic_dec_and_test variation before object free at line 2363.
drivers/media/usb/s2255/s2255drv.c:1557:5-24: WARNING: atomic_dec_and_test variation before object free at line 1558.
Link: https://lore.kernel.org/linux-media/20240429-fix-cocci-v3-11-3c4865f5a4b0@xxxxxxxxxxxx
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/media/usb/s2255/s2255drv.c b/drivers/media/usb/s2255/s2255drv.c
index 7ed526306816a..845869240abee 100644
--- a/drivers/media/usb/s2255/s2255drv.c
+++ b/drivers/media/usb/s2255/s2255drv.c
@@ -247,7 +247,7 @@ struct s2255_vc {
struct s2255_dev {
struct s2255_vc vc[MAX_CHANNELS];
struct v4l2_device v4l2_dev;
- atomic_t num_channels;
+ refcount_t num_channels;
int frames;
struct mutex lock; /* channels[].vdev.lock */
struct mutex cmdlock; /* protects cmdbuf */
@@ -1552,11 +1552,11 @@ static void s2255_video_device_release(struct video_device *vdev)
container_of(vdev, struct s2255_vc, vdev);
dprintk(dev, 4, "%s, chnls: %d\n", __func__,
- atomic_read(&dev->num_channels));
+ refcount_read(&dev->num_channels));
v4l2_ctrl_handler_free(&vc->hdl);
- if (atomic_dec_and_test(&dev->num_channels))
+ if (refcount_dec_and_test(&dev->num_channels))
s2255_destroy(dev);
return;
}
@@ -1661,7 +1661,7 @@ static int s2255_probe_v4l(struct s2255_dev *dev)
"failed to register video device!\n");
break;
}
- atomic_inc(&dev->num_channels);
+ refcount_inc(&dev->num_channels);
v4l2_info(&dev->v4l2_dev, "V4L2 device registered as %s\n",
video_device_node_name(&vc->vdev));
@@ -1669,11 +1669,11 @@ static int s2255_probe_v4l(struct s2255_dev *dev)
pr_info("Sensoray 2255 V4L driver Revision: %s\n",
S2255_VERSION);
/* if no channels registered, return error and probe will fail*/
- if (atomic_read(&dev->num_channels) == 0) {
+ if (refcount_read(&dev->num_channels) == 0) {
v4l2_device_unregister(&dev->v4l2_dev);
return ret;
}
- if (atomic_read(&dev->num_channels) != MAX_CHANNELS)
+ if (refcount_read(&dev->num_channels) != MAX_CHANNELS)
pr_warn("s2255: Not all channels available.\n");
return 0;
}
@@ -2222,7 +2222,7 @@ static int s2255_probe(struct usb_interface *interface,
goto errorFWDATA1;
}
- atomic_set(&dev->num_channels, 0);
+ refcount_set(&dev->num_channels, 0);
dev->pid = id->idProduct;
dev->fw_data = kzalloc(sizeof(struct s2255_fw), GFP_KERNEL);
if (!dev->fw_data)
@@ -2342,12 +2342,12 @@ static void s2255_disconnect(struct usb_interface *interface)
{
struct s2255_dev *dev = to_s2255_dev(usb_get_intfdata(interface));
int i;
- int channels = atomic_read(&dev->num_channels);
+ int channels = refcount_read(&dev->num_channels);
mutex_lock(&dev->lock);
v4l2_device_disconnect(&dev->v4l2_dev);
mutex_unlock(&dev->lock);
/*see comments in the uvc_driver.c usb disconnect function */
- atomic_inc(&dev->num_channels);
+ refcount_inc(&dev->num_channels);
/* unregister each video device. */
for (i = 0; i < channels; i++)
video_unregister_device(&dev->vc[i].vdev);
@@ -2360,7 +2360,7 @@ static void s2255_disconnect(struct usb_interface *interface)
dev->vc[i].vidstatus_ready = 1;
wake_up(&dev->vc[i].wait_vidstatus);
}
- if (atomic_dec_and_test(&dev->num_channels))
+ if (refcount_dec_and_test(&dev->num_channels))
s2255_destroy(dev);
dev_info(&interface->dev, "%s\n", __func__);
}
