Hi Hans,
Thanks for the patch.
On Wednesday 25 May 2011 15:33:52 Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>
> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> ---
> drivers/media/video/v4l2-ctrls.c | 31 +++++++++++++++++++++++++++++++
> include/media/v4l2-ctrls.h | 25 +++++++++++++++++++++++++
> 2 files changed, 56 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/media/video/v4l2-ctrls.c
> b/drivers/media/video/v4l2-ctrls.c index e2a7ac7..9807a20 100644
> --- a/drivers/media/video/v4l2-ctrls.c
> +++ b/drivers/media/video/v4l2-ctrls.c
> @@ -831,6 +831,22 @@ int v4l2_ctrl_handler_init(struct v4l2_ctrl_handler
> *hdl, }
> EXPORT_SYMBOL(v4l2_ctrl_handler_init);
>
> +/* Count the number of controls */
> +unsigned v4l2_ctrl_handler_cnt(struct v4l2_ctrl_handler *hdl)
> +{
> + struct v4l2_ctrl_ref *ref;
> + unsigned cnt = 0;
> +
> + if (hdl == NULL)
> + return 0;
> + mutex_lock(&hdl->lock);
> + list_for_each_entry(ref, &hdl->ctrl_refs, node)
> + cnt++;
As you don't use the entry, you can replace list_for_each_entry with
list_for_each.
Should the handler keep a controls count ? In that case you wouldn't need this
function.
> + mutex_unlock(&hdl->lock);
> + return cnt;
> +}
> +EXPORT_SYMBOL(v4l2_ctrl_handler_cnt);
> +
> /* Free all controls and control refs */
> void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl)
> {
> @@ -1999,3 +2015,18 @@ void v4l2_ctrl_del_fh(struct v4l2_ctrl *ctrl, struct
> v4l2_fh *fh) v4l2_ctrl_unlock(ctrl);
> }
> EXPORT_SYMBOL(v4l2_ctrl_del_fh);
> +
> +int v4l2_ctrl_sub_fh(struct v4l2_fh *fh, struct v4l2_event_subscription
> *sub, + unsigned n)
I would rename this to v4l2_ctrl_subscribe_fh(). I had trouble understanding
what v4l2_ctrl_sub_fh() before reading the documentation. sub makes me think
about sub-devices and subtract, not subscription.
> +{
> + int ret = 0;
> +
> + if (!fh->events)
> + ret = v4l2_event_init(fh);
> + if (!ret)
> + ret = v4l2_event_alloc(fh, n);
> + if (!ret)
> + ret = v4l2_event_subscribe(fh, sub);
I tend to return errors when they occur instead of continuing to the end of
the function. Handling errors on the spot makes code easier to read in my
opinion, as I expect the main code flow to be the error-free path.
> + return ret;
> +}
--
Regards,
Laurent Pinchart
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