On Wed, Jun 28, 2023 at 12:09 PM sun yq <yqsun1997@xxxxxxxxx> wrote:
>
> Hi Alain,
>
> May I ask if you are the person involved in the code?We should listen
> to the opinions of the code owner.
Please don't top post.
Alain has a valid point. Please describe in detail how you are running
into or detecting this problem. Are you running into this for real? Or
is this from a static analyzer? Or are you simply eyeballing the issue?
ChenYu
> On Wed, Jun 28, 2023 at 2:34 PM Alain Volmat <alain.volmat@xxxxxxxxxxx> wrote:
> >
> > Hi,
> >
> > On Wed, Jun 28, 2023 at 07:28:54AM +0800, sun yq wrote:
> > > Hi,
> > > Because there are many functions using the plane, increasing the max
> > > number of the plane is to maximize the solution to all possible oob
> > > places.
> >
> > I don't think it is the right approach then. If the HW is only handling
> > 3 planes, there should be no reason to have to allocate for 8 planes. I
> > suspect that this 8 value is coming from the maximum allowed plane
> > number in V4L2 right ?
> > INHO driver should simply be fixed to ensure that num_plane won't go
> > higher than the real number of plane allocated in the structures.
> > It should be possible to get the num_plane value from the format
> > selected.
> >
> > Alain
> >
> > >
> > > On Tue, Jun 27, 2023 at 10:06 PM Alain Volmat <alain.volmat@xxxxxxxxxxx> wrote:
> > > >
> > > > Hi,
> > > >
> > > > On Tue, Jun 27, 2023 at 04:27:31PM +0800, yqsun1997@xxxxxxxxx wrote:
> > > > > From: yqsun1997 <yqsun1997@xxxxxxxxx>
> > > > >
> > > > > Because format in struct img_image_buffer max index is IMG_MAX_PLANES ==3,
> > > > > The num_planes max index is 8.so will be OOB like in mdp_prepare_buffer.
> > > >
> > > > Similarly as your other patch, could you describe why you need to
> > > > increase the IMG_MAX_PLANES while I suspect your driver only needs to
> > > > deal with 3 planes. While the maximum num_planes value that can be
> > > > given by the user is 8, this has to be first compared to the configured
> > > > format prior to reaching this function.
> > > >
> > > > >
> > > > > static void mdp_prepare_buffer(struct img_image_buffer *b,
> > > > > struct mdp_frame *frame, struct vb2_buffer *vb)
> > > > > {
> > > > > struct v4l2_pix_format_mplane *pix_mp = &frame->format.fmt.pix_mp;
> > > > > unsigned int i;
> > > > >
> > > > > b->format.colorformat = frame->mdp_fmt->mdp_color;
> > > > > b->format.ycbcr_prof = frame->ycbcr_prof;
> > > > > for (i = 0; i < pix_mp->num_planes; ++i) {
> > > > > u32 stride = mdp_fmt_get_stride(frame->mdp_fmt,
> > > > > pix_mp->plane_fmt[i].bytesperline, i);
> > > > >
> > > > > b->format.plane_fmt[i].stride = stride; //oob
> > > > > ......
> > > > >
> > > > > Signed-off-by: yqsun1997 <yqsun1997@xxxxxxxxx>
> > > > > ---
> > > > > drivers/media/platform/mediatek/mdp3/mtk-mdp3-type.h | 2 +-
> > > > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > > > >
> > > > > diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-type.h b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-type.h
> > > > > index ae0396806..e2e991a34 100644
> > > > > --- a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-type.h
> > > > > +++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-type.h
> > > > > @@ -11,7 +11,7 @@
> > > > >
> > > > > #define IMG_MAX_HW_INPUTS 3
> > > > > #define IMG_MAX_HW_OUTPUTS 4
> > > > > -#define IMG_MAX_PLANES 3
> > > > > +#define IMG_MAX_PLANES 8
> > > > > #define IMG_MAX_COMPONENTS 20
> > > > >
> > > > > struct img_crop {
> > > > > --
> > > > > 2.39.2
> > > > >
> > > >
> > > > Regards,
> > > > Alain
>
