On Wed, 2019-05-29 at 16:41 +0200, Hans Verkuil wrote:
> On 5/3/19 1:42 PM, Boris Brezillon wrote:
> > Make sure the default value at least passes the std_validate() tests.
> >
> > Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> > ---
> > drivers/media/v4l2-core/v4l2-ctrls.c | 20 +++++++++++++++++++-
> > 1 file changed, 19 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> > index b1ae2e555c68..19d40cc6e565 100644
> > --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> > +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> > @@ -1461,7 +1461,14 @@ static bool std_equal(const struct v4l2_ctrl *ctrl, u32 idx,
> > static void std_init(const struct v4l2_ctrl *ctrl, u32 idx,
> > union v4l2_ctrl_ptr ptr)
> > {
> > - switch (ctrl->type) {
> > + struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
> > +
> > + /*
> > + * The cast is needed to get rid of a gcc warning complaining that
> > + * V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS is not part of the
> > + * v4l2_ctrl_type enum.
> > + */
> > + switch ((u32)ctrl->type) {
> > case V4L2_CTRL_TYPE_STRING:
> > idx *= ctrl->elem_size;
> > memset(ptr.p_char + idx, ' ', ctrl->minimum);
> > @@ -1486,6 +1493,17 @@ static void std_init(const struct v4l2_ctrl *ctrl, u32 idx,
> > case V4L2_CTRL_TYPE_U32:
> > ptr.p_u32[idx] = ctrl->default_value;
> > break;
> > + case V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS:
> > + p_mpeg2_slice_params = ptr.p;
> > + /* 4:2:0 */
> > + p_mpeg2_slice_params->sequence.chroma_format = 1;
> > + /* 8 bits */
> > + p_mpeg2_slice_params->picture.intra_dc_precision = 0;
> > + /* interlaced top field */
> > + p_mpeg2_slice_params->picture.picture_structure = 1;
> > + p_mpeg2_slice_params->picture.picture_coding_type =
> > + V4L2_MPEG2_PICTURE_CODING_TYPE_I;
>
> Oops, this isn't complete. It should still zero the p_mpeg2_slice_params
> struct first. Right now any fields not explicitly set just have whatever
> was in memory.
>
> Can you post a patch fixing this?
>
>
I was wondering if we want to zero all the cases, and not just
the struct types ones.
Or a different approach would be to define statically-allocated default
structs, and init-assign to them. Although this take more space,
and has no benefits, except maybe code clarity.
OTOH, I can push a quick fix if you want, just zeroing this struct.
