Re: [PATCH v6 1/7] media: v4l2-core: Implement v4l2_ctrl_new_std_compound

From: Ricardo Ribalda Delgado
Date: Wed Sep 25 2019 - 17:04:59 EST

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In reply to: Jacopo Mondi: "Re: [PATCH v6 1/7] media: v4l2-core: Implement v4l2_ctrl_new_std_compound"
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Hi Jacopo

Thanks for your review!

On Wed, Sep 25, 2019 at 10:18 AM Jacopo Mondi <jacopo@xxxxxxxxxx> wrote:
>
> Hi Ricardo,
>
> On Fri, Sep 20, 2019 at 03:51:31PM +0200, Ricardo Ribalda Delgado wrote:
> > Currently compound controls do not have a simple way of initializing its
> > values. This results in ofuscated code with type_ops init.
> >
> > This patch introduces a new field on the control with the default value
> > for the compound control that can be set with the brand new
> > v4l2_ctrl_new_std_compound function
> >
> > Suggested-by: Hans Verkuil <hverkuil@xxxxxxxxx>
> > Signed-off-by: Ricardo Ribalda Delgado <ricardo@xxxxxxxxxxx>
> > ---
> > drivers/media/v4l2-core/v4l2-ctrls.c | 50 ++++++++++++++++++++++++----
> > include/media/v4l2-ctrls.h | 22 +++++++++++-
> > 2 files changed, 64 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> > index 1d8f38824631..219d8aeefa20 100644
> > --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> > +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> > @@ -29,6 +29,8 @@
> > #define call_op(master, op) \
> > (has_op(master, op) ? master->ops->op(master) : 0)
> >
> > +static const union v4l2_ctrl_ptr ptr_null;
> > +
> > /* Internal temporary helper struct, one for each v4l2_ext_control */
> > struct v4l2_ctrl_helper {
> > /* Pointer to the control reference of the master control */
> > @@ -1530,7 +1532,10 @@ static void std_init_compound(const struct v4l2_ctrl *ctrl, u32 idx,
> > struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
> > void *p = ptr.p + idx * ctrl->elem_size;
> >
> > - memset(p, 0, ctrl->elem_size);
> > + if (ctrl->p_def.p)
> > + memcpy(p, ctrl->p_def.p, ctrl->elem_size);
> > + else
> > + memset(p, 0, ctrl->elem_size);
> >
> > /*
> > * The cast is needed to get rid of a gcc warning complaining that
> > @@ -2354,7 +2359,8 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
> > s64 min, s64 max, u64 step, s64 def,
> > const u32 dims[V4L2_CTRL_MAX_DIMS], u32 elem_size,
> > u32 flags, const char * const *qmenu,
> > - const s64 *qmenu_int, void *priv)
> > + const s64 *qmenu_int, const union v4l2_ctrl_ptr p_def,
> > + void *priv)
> > {
> > struct v4l2_ctrl *ctrl;
> > unsigned sz_extra;
> > @@ -2460,6 +2466,9 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
> > is_array)
> > sz_extra += 2 * tot_ctrl_size;
> >
> > + if (type >= V4L2_CTRL_COMPOUND_TYPES && p_def.p)
> > + sz_extra += elem_size;
> > +
>
> I'm not sure I get how sz_extra is used in this function and what's
> its purpose, just be aware that the previous if() condition already
>
> sz_extra += 2 * tot_ctrl_size
>
> for compound controls.
>
> Are you just making space for the new p_def elements ? Should't you
> then use tot_cltr_size ? In patch 3 you add support for AREA which has
> a single element, but could p_def in future transport multiple values?
>

I am making space for p_def. I only want to make space for one
element, because that value will be used for all of them if there is
an array.
In case the user wants to provide a different value per element of the
array he has to provide a function initializer, just like with the not
compo\

> > ctrl = kvzalloc(sizeof(*ctrl) + sz_extra, GFP_KERNEL);
> > if (ctrl == NULL) {
> > handler_set_err(hdl, -ENOMEM);
> > @@ -2503,6 +2512,12 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
> > ctrl->p_new.p = &ctrl->val;
> > ctrl->p_cur.p = &ctrl->cur.val;
> > }
> > +
> > + if (type >= V4L2_CTRL_COMPOUND_TYPES && p_def.p) {
> > + ctrl->p_def.p = ctrl->p_cur.p + tot_ctrl_size;
> > + memcpy(ctrl->p_def.p, p_def.p, elem_size);
> > + }
> > +
> > for (idx = 0; idx < elems; idx++) {
> > ctrl->type_ops->init(ctrl, idx, ctrl->p_cur);
> > ctrl->type_ops->init(ctrl, idx, ctrl->p_new);
> > @@ -2554,7 +2569,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
> > type, min, max,
> > is_menu ? cfg->menu_skip_mask : step, def,
> > cfg->dims, cfg->elem_size,
> > - flags, qmenu, qmenu_int, priv);
> > + flags, qmenu, qmenu_int, ptr_null, priv);
> > if (ctrl)
> > ctrl->is_private = cfg->is_private;
> > return ctrl;
> > @@ -2579,7 +2594,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
> > }
> > return v4l2_ctrl_new(hdl, ops, NULL, id, name, type,
> > min, max, step, def, NULL, 0,
> > - flags, NULL, NULL, NULL);
> > + flags, NULL, NULL, ptr_null, NULL);
> > }
> > EXPORT_SYMBOL(v4l2_ctrl_new_std);
> >
> > @@ -2612,7 +2627,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
> > }
> > return v4l2_ctrl_new(hdl, ops, NULL, id, name, type,
> > 0, max, mask, def, NULL, 0,
> > - flags, qmenu, qmenu_int, NULL);
> > + flags, qmenu, qmenu_int, ptr_null, NULL);
> > }
> > EXPORT_SYMBOL(v4l2_ctrl_new_std_menu);
> >
> > @@ -2644,11 +2659,32 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
> > }
> > return v4l2_ctrl_new(hdl, ops, NULL, id, name, type,
> > 0, max, mask, def, NULL, 0,
> > - flags, qmenu, NULL, NULL);
> > + flags, qmenu, NULL, ptr_null, NULL);
> >
> > }
> > EXPORT_SYMBOL(v4l2_ctrl_new_std_menu_items);
> >
> > +/* Helper function for standard compound controls */
> > +struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
> > + const struct v4l2_ctrl_ops *ops, u32 id,
> > + const union v4l2_ctrl_ptr p_def)
> > +{
> > + const char *name;
> > + enum v4l2_ctrl_type type;
> > + u32 flags;
> > + s64 min, max, step, def;
> > +
> > + v4l2_ctrl_fill(id, &name, &type, &min, &max, &step, &def, &flags);
> > + if (type < V4L2_CTRL_COMPOUND_TYPES) {
> > + handler_set_err(hdl, -EINVAL);
> > + return NULL;
> > + }
> > + return v4l2_ctrl_new(hdl, ops, NULL, id, name, type,
> > + min, max, step, def, NULL, 0,
> > + flags, NULL, NULL, p_def, NULL);
> > +}
> > +EXPORT_SYMBOL(v4l2_ctrl_new_std_compound);
> > +
> > /* Helper function for standard integer menu controls */
> > struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
> > const struct v4l2_ctrl_ops *ops,
> > @@ -2669,7 +2705,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
> > }
> > return v4l2_ctrl_new(hdl, ops, NULL, id, name, type,
> > 0, max, 0, def, NULL, 0,
> > - flags, NULL, qmenu_int, NULL);
> > + flags, NULL, qmenu_int, ptr_null, NULL);
> > }
> > EXPORT_SYMBOL(v4l2_ctrl_new_int_menu);
> >
> > diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
> > index 570ff4b0205a..4b356df850a1 100644
> > --- a/include/media/v4l2-ctrls.h
> > +++ b/include/media/v4l2-ctrls.h
> > @@ -200,6 +200,9 @@ typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
> > * not freed when the control is deleted. Should this be needed
> > * then a new internal bitfield can be added to tell the framework
> > * to free this pointer.
> > + * @p_def: The control's default value represented via a union which
> > + * provides a standard way of accessing control types
> > + * through a pointer (for compound controls only).
> > * @p_cur: The control's current value represented via a union which
> > * provides a standard way of accessing control types
> > * through a pointer.
> > @@ -254,6 +257,7 @@ struct v4l2_ctrl {
> > s32 val;
> > } cur;
> >
> > + union v4l2_ctrl_ptr p_def;
> > union v4l2_ctrl_ptr p_new;
> > union v4l2_ctrl_ptr p_cur;
> > };
> > @@ -618,7 +622,6 @@ struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
> > struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
> > const struct v4l2_ctrl_ops *ops,
> > u32 id, u8 max, u64 mask, u8 def);
> > -
>
> This seems unrelated

Good catch!
>
> > /**
> > * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
> > * with driver specific menu.
> > @@ -646,6 +649,23 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
> > u64 mask, u8 def,
> > const char * const *qmenu);
> >
> > +/**
> > + * v4l2_ctrl_new_std_compound() - Allocate and initialize a new standard V4L2
> > + * compound control.
> > + *
> > + * @hdl: The control handler.
> > + * @ops: The control ops.
> > + * @id: The control ID.
> > + * @p_def: The control's p_def value.
>
> Nit:
> s/p_def value/default value/ ?
>
>
> Thanks
> j

Fixing all and uploading to my github waiting for more reviews :)
>
> > + *
> > + * Sames as v4l2_ctrl_new_std(), but with support to compound controls, thanks
> > + * to the @p_def field.
> > + *
> > + */
> > +struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
> > + const struct v4l2_ctrl_ops *ops, u32 id,
> > + const union v4l2_ctrl_ptr p_def);
> > +
> > /**
> > * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
> > *
> > --
> > 2.23.0
> >

--
Ricardo Ribalda

Next message: Navid Emamdoost: "[PATCH] soc: renesas: rcar-sysc: fix memory leak in rcar_sysc_pd_init"
Previous message: Kees Cook: "[PATCH] audit: Report suspicious O_CREAT usage"
In reply to: Jacopo Mondi: "Re: [PATCH v6 1/7] media: v4l2-core: Implement v4l2_ctrl_new_std_compound"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]