Em Sat, 4 Aug 2018 14:45:04 +0200
Hans Verkuil <hverk...@xs4all.nl> escreveu:
> From: Hans Verkuil <hans.verk...@cisco.com>
>
> To store request data the handler_new_ref() allocates memory
> for it if needed.
>
> Signed-off-by: Hans Verkuil <hans.verk...@cisco.com>
> ---
> drivers/media/v4l2-core/v4l2-ctrls.c | 20 ++++++++++++++++----
> 1 file changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c
> b/drivers/media/v4l2-core/v4l2-ctrls.c
> index b33a8bee82b0..171ab389afdd 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -2018,13 +2018,18 @@ EXPORT_SYMBOL(v4l2_ctrl_find);
> /* Allocate a new v4l2_ctrl_ref and hook it into the handler. */
> static int handler_new_ref(struct v4l2_ctrl_handler *hdl,
> struct v4l2_ctrl *ctrl,
> - bool from_other_dev)
> + struct v4l2_ctrl_ref **ctrl_ref,
> + bool from_other_dev, bool allocate_req)
> {
> struct v4l2_ctrl_ref *ref;
> struct v4l2_ctrl_ref *new_ref;
> u32 id = ctrl->id;
> u32 class_ctrl = V4L2_CTRL_ID2WHICH(id) | 1;
> int bucket = id % hdl->nr_of_buckets; /* which bucket to use */
> + unsigned int sz_extra = 0;
Nitpick: I would name it size_extra_req, to make clear its usage.
Once renamed:
Reviewed-by: Mauro Carvalho Chehab <mchehab+sams...@kernel.org>
> +
> + if (ctrl_ref)
> + *ctrl_ref = NULL;
>
> /*
> * Automatically add the control class if it is not yet present and
> @@ -2038,11 +2043,16 @@ static int handler_new_ref(struct v4l2_ctrl_handler
> *hdl,
> if (hdl->error)
> return hdl->error;
>
> - new_ref = kzalloc(sizeof(*new_ref), GFP_KERNEL);
> + if (allocate_req)
> + sz_extra = ctrl->elems * ctrl->elem_size;
> + new_ref = kzalloc(sizeof(*new_ref) + sz_extra, GFP_KERNEL);
> if (!new_ref)
> return handler_set_err(hdl, -ENOMEM);
> new_ref->ctrl = ctrl;
> new_ref->from_other_dev = from_other_dev;
> + if (sz_extra)
> + new_ref->p_req.p = &new_ref[1];
> +
> if (ctrl->handler == hdl) {
> /* By default each control starts in a cluster of its own.
> new_ref->ctrl is basically a cluster array with one
> @@ -2082,6 +2092,8 @@ static int handler_new_ref(struct v4l2_ctrl_handler
> *hdl,
> /* Insert the control node in the hash */
> new_ref->next = hdl->buckets[bucket];
> hdl->buckets[bucket] = new_ref;
> + if (ctrl_ref)
> + *ctrl_ref = new_ref;
>
> unlock:
> mutex_unlock(hdl->lock);
> @@ -2223,7 +2235,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct
> v4l2_ctrl_handler *hdl,
> ctrl->type_ops->init(ctrl, idx, ctrl->p_new);
> }
>
> - if (handler_new_ref(hdl, ctrl, false)) {
> + if (handler_new_ref(hdl, ctrl, NULL, false, false)) {
> kvfree(ctrl);
> return NULL;
> }
> @@ -2416,7 +2428,7 @@ int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
> /* Filter any unwanted controls */
> if (filter && !filter(ctrl))
> continue;
> - ret = handler_new_ref(hdl, ctrl, from_other_dev);
> + ret = handler_new_ref(hdl, ctrl, NULL, from_other_dev, false);
> if (ret)
> break;
> }
Thanks,
Mauro
