Em Thu, 3 May 2018 16:52:59 +0200
Hans Verkuil <hverkuil@xxxxxxxxx> escreveu:
> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>
> Embed and initialize a media_request_object in struct v4l2_ctrl_handler.
>
> Add a p_req field to struct v4l2_ctrl_ref that will store the
> request value.
>
> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-ctrls.c | 1 +
> include/media/v4l2-ctrls.h | 7 +++++++
> 2 files changed, 8 insertions(+)
>
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> index aa1dd2015e84..d09f49530d9e 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -1880,6 +1880,7 @@ int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
> sizeof(hdl->buckets[0]),
> GFP_KERNEL | __GFP_ZERO);
> hdl->error = hdl->buckets ? 0 : -ENOMEM;
> + media_request_object_init(&hdl->req_obj);
> return hdl->error;
> }
> EXPORT_SYMBOL(v4l2_ctrl_handler_init_class);
> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
> index d26b8ddebb56..76352eb59f14 100644
> --- a/include/media/v4l2-ctrls.h
> +++ b/include/media/v4l2-ctrls.h
> @@ -20,6 +20,7 @@
> #include <linux/list.h>
> #include <linux/mutex.h>
> #include <linux/videodev2.h>
> +#include <media/media-request.h>
>
> /* forward references */
> struct file;
> @@ -249,6 +250,8 @@ struct v4l2_ctrl {
> * ``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``.
> * @from_other_dev: If true, then @ctrl was defined in another
> * device than the &struct v4l2_ctrl_handler.
> + * @p_req: The request value. Only used if the control handler
> + * is bound to a media request.
Could you please better elaborate the description of this field?
I read this patch dozen times to understand what you meant by
"request value", as I would be expecting here a "media_request_"
object or something similar. Instead, what you meant to say is that
@p_req will be used to cache the data passed via a request API call,
while the request is not handled yet, right?
> *
> * Each control handler has a list of these refs. The list_head is used to
> * keep a sorted-by-control-ID list of all controls, while the next pointer
> @@ -260,6 +263,7 @@ struct v4l2_ctrl_ref {
> struct v4l2_ctrl *ctrl;
> struct v4l2_ctrl_helper *helper;
> bool from_other_dev;
> + union v4l2_ctrl_ptr p_req;
> };
>
> /**
> @@ -283,6 +287,8 @@ struct v4l2_ctrl_ref {
> * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
> * @nr_of_buckets: Total number of buckets in the array.
> * @error: The error code of the first failed control addition.
> + * @req_obj: The &struct media_request_object, used to link into a
> + * &struct media_request.
I would document that there is kref is inside @req_obj, as we can't
add another kref here later.
> */
> struct v4l2_ctrl_handler {
> struct mutex _lock;
> @@ -295,6 +301,7 @@ struct v4l2_ctrl_handler {
> void *notify_priv;
> u16 nr_of_buckets;
> int error;
> + struct media_request_object req_obj;
> };
>
> /**
Thanks,
Mauro
