Hi Ricardo,
On 10/04/2013 03:49 PM, Ricardo Ribalda Delgado wrote:
> A video device opened and streaming in io emulator mode can only stop
> streamming if its file descriptor is closed.
>
> There are some parameters that can only be changed if the device is not
> streaming. Also, the power consumption of a device streaming could be
> different than one not streaming.
>
> With this patch a video device opened in io emulator can be stopped on
> demand.
Why would you want this? If you can call STREAMOFF, why not use stream I/O
all the way? That's much more efficient than read() anyway.
Unless there is a very good use-case, I don't see a good reason for mixing
file I/O with streaming I/O ioctls.
Regards,
Hans
>
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.riba...@gmail.com>
> ---
> drivers/media/v4l2-core/videobuf2-core.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/videobuf2-core.c
> b/drivers/media/v4l2-core/videobuf2-core.c
> index 9fc4bab..097fba8 100644
> --- a/drivers/media/v4l2-core/videobuf2-core.c
> +++ b/drivers/media/v4l2-core/videobuf2-core.c
> @@ -1686,6 +1686,7 @@ int vb2_streamon(struct vb2_queue *q, enum
> v4l2_buf_type type)
> }
> EXPORT_SYMBOL_GPL(vb2_streamon);
>
> +static int __vb2_cleanup_fileio(struct vb2_queue *q);
>
> /**
> * vb2_streamoff - stop streaming
> @@ -1704,11 +1705,6 @@ EXPORT_SYMBOL_GPL(vb2_streamon);
> */
> int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
> {
> - if (q->fileio) {
> - dprintk(1, "streamoff: file io in progress\n");
> - return -EBUSY;
> - }
> -
> if (type != q->type) {
> dprintk(1, "streamoff: invalid stream type\n");
> return -EINVAL;
> @@ -1719,6 +1715,11 @@ int vb2_streamoff(struct vb2_queue *q, enum
> v4l2_buf_type type)
> return -EINVAL;
> }
>
> + if (q->fileio) {
> + __vb2_cleanup_fileio(q);
> + return 0;
> + }
> +
> /*
> * Cancel will pause streaming and remove all buffers from the driver
> * and videobuf, effectively returning control over them to userspace.
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
