On 2/27/19 6:07 PM, Ezequiel Garcia wrote:
> In preparation to cleanup the debug logic, simplify the dev_debug
> usage. In particular, make sure that a single flag is used to
> control each debug print.
>
> Before this commit V4L2_DEV_DEBUG_STREAMING and V4L2_DEV_DEBUG_FOP
> were needed to enable read and write debugging. After this commit
> only the former is needed.
The original idea was that ioctls are logged with V4L2_DEV_DEBUG_IOCTL
and file ops with V4L2_DEV_DEBUG_FOP. And to see the streaming ioctls
or fops you would have to add V4L2_DEV_DEBUG_STREAMING in addition to
DEBUG_IOCTL/FOP.
This patch changes the behavior in that the streaming fops are now
solely controlled by V4L2_DEV_DEBUG_STREAMING.
I do agree with this change, but this requires that the same change is
done for the streaming ioctls (DQBUF/QBUF) and that the documentation in
Documentation/media/kapi/v4l2-dev.rst is updated (section "video device
debugging").
Of course, the documentation should also mention the new dev_debug
module parameter and the new debug flag for debugging controls.
Regards,
Hans
>
> Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-dev.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
> index d7528f82a66a..34e4958663bf 100644
> --- a/drivers/media/v4l2-core/v4l2-dev.c
> +++ b/drivers/media/v4l2-core/v4l2-dev.c
> @@ -315,8 +315,7 @@ static ssize_t v4l2_read(struct file *filp, char __user *buf,
> return -EINVAL;
> if (video_is_registered(vdev))
> ret = vdev->fops->read(filp, buf, sz, off);
> - if ((vdev->dev_debug & V4L2_DEV_DEBUG_FOP) &&
> - (vdev->dev_debug & V4L2_DEV_DEBUG_STREAMING))
> + if (vdev->dev_debug & V4L2_DEV_DEBUG_STREAMING)
> dprintk("%s: read: %zd (%d)\n",
> video_device_node_name(vdev), sz, ret);
> return ret;
> @@ -332,8 +331,7 @@ static ssize_t v4l2_write(struct file *filp, const char __user *buf,
> return -EINVAL;
> if (video_is_registered(vdev))
> ret = vdev->fops->write(filp, buf, sz, off);
> - if ((vdev->dev_debug & V4L2_DEV_DEBUG_FOP) &&
> - (vdev->dev_debug & V4L2_DEV_DEBUG_STREAMING))
> + if (vdev->dev_debug & V4L2_DEV_DEBUG_STREAMING)
> dprintk("%s: write: %zd (%d)\n",
> video_device_node_name(vdev), sz, ret);
> return ret;
>
