Re: [RFC PATCH 2/3] drm: Adjust atomic checks for solid fill color

[Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>]

On 10/29/2022 4:38 AM, Dmitry Baryshkov wrote:
> On 29/10/2022 01:59, Jessica Zhang wrote:
> > Loosen the requirements for atomic and legacy commit so that, in cases
> > where solid fill planes is enabled (and FB_ID is NULL), the commit can
> > still go through.
> >
> > In addition, add framebuffer NULL checks in other areas to account for
> > FB being NULL when solid fill is enabled.
> >
> > Signed-off-by: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/drm_atomic.c        | 68 ++++++++++++++++-------------
> >   drivers/gpu/drm/drm_atomic_helper.c | 34 +++++++++------
> >   drivers/gpu/drm/drm_plane.c         |  8 ++--
> >   include/drm/drm_atomic_helper.h     |  5 ++-
> >   4 files changed, 64 insertions(+), 51 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> > index f197f59f6d99..b576ed221431 100644
> > --- a/drivers/gpu/drm/drm_atomic.c
> > +++ b/drivers/gpu/drm/drm_atomic.c
> > @@ -601,8 +601,10 @@ static int drm_atomic_plane_check(const struct 
> > drm_plane_state *old_plane_state,
> >       uint32_t num_clips;
> >       int ret;
> > -    /* either *both* CRTC and FB must be set, or neither */
> > -    if (crtc && !fb) {
> > +    /* When color_fill is disabled,
> > +     * either *both* CRTC and FB must be set, or neither
> > +     */
> > +    if (crtc && !fb && !new_plane_state->color_fill) {
>
> Using !color_fill sounds bad. It would disallow using black as the plane 
> fill color. I think, you need to check color_fill_format instead.

Hey Dmitry,

Good point -- acked.

> >           drm_dbg_atomic(plane->dev, "[PLANE:%d:%s] CRTC set but no 
> > FB\n",
> >                      plane->base.id, plane->name);
> >           return -EINVAL;
> > @@ -626,14 +628,16 @@ static int drm_atomic_plane_check(const struct 
> > drm_plane_state *old_plane_state,
> >       }
>
>
> Don't we need to check that the color_fill_format is supported too?

Acked.

> >       /* Check whether this plane supports the fb pixel format. */
> > -    ret = drm_plane_check_pixel_format(plane, fb->format->format,
> > -                       fb->modifier);
> > -    if (ret) {
> > -        drm_dbg_atomic(plane->dev,
> > -                   "[PLANE:%d:%s] invalid pixel format %p4cc, 
> > modifier 0x%llx\n",
> > -                   plane->base.id, plane->name,
> > -                   &fb->format->format, fb->modifier);
> > -        return ret;
> > +    if (fb) {
> > +        ret = drm_plane_check_pixel_format(plane, fb->format->format,
> > +                           fb->modifier);
> > +
> > +        if (ret)
> > +            drm_dbg_atomic(plane->dev,
> > +                       "[PLANE:%d:%s] invalid pixel format %p4cc, 
> > modifier 0x%llx\n",
> > +                       plane->base.id, plane->name,
> > +                       &fb->format->format, fb->modifier);
> > +            return ret;
> >       }
> >       /* Give drivers some help against integer overflows */
> > @@ -649,28 +653,30 @@ static int drm_atomic_plane_check(const struct 
> > drm_plane_state *old_plane_state,
> >           return -ERANGE;
> >       }
> > -    fb_width = fb->width << 16;
> > -    fb_height = fb->height << 16;
> > +    if (fb) {
> > +        fb_width = fb->width << 16;
> > +        fb_height = fb->height << 16;
> > -    /* Make sure source coordinates are inside the fb. */
> > -    if (new_plane_state->src_w > fb_width ||
> > -        new_plane_state->src_x > fb_width - new_plane_state->src_w ||
> > -        new_plane_state->src_h > fb_height ||
> > -        new_plane_state->src_y > fb_height - new_plane_state->src_h) {
> > -        drm_dbg_atomic(plane->dev,
> > -                   "[PLANE:%d:%s] invalid source coordinates "
> > -                   "%u.%06ux%u.%06u+%u.%06u+%u.%06u (fb %ux%u)\n",
> > -                   plane->base.id, plane->name,
> > -                   new_plane_state->src_w >> 16,
> > -                   ((new_plane_state->src_w & 0xffff) * 15625) >> 10,
> > -                   new_plane_state->src_h >> 16,
> > -                   ((new_plane_state->src_h & 0xffff) * 15625) >> 10,
> > -                   new_plane_state->src_x >> 16,
> > -                   ((new_plane_state->src_x & 0xffff) * 15625) >> 10,
> > -                   new_plane_state->src_y >> 16,
> > -                   ((new_plane_state->src_y & 0xffff) * 15625) >> 10,
> > -                   fb->width, fb->height);
> > -        return -ENOSPC;
> > +        /* Make sure source coordinates are inside the fb. */
> > +        if (new_plane_state->src_w > fb_width ||
> > +            new_plane_state->src_x > fb_width - 
> > new_plane_state->src_w ||
> > +            new_plane_state->src_h > fb_height ||
> > +            new_plane_state->src_y > fb_height - 
> > new_plane_state->src_h) {
> > +            drm_dbg_atomic(plane->dev,
> > +                       "[PLANE:%d:%s] invalid source coordinates "
> > +                       "%u.%06ux%u.%06u+%u.%06u+%u.%06u (fb %ux%u)\n",
> > +                       plane->base.id, plane->name,
> > +                       new_plane_state->src_w >> 16,
> > +                       ((new_plane_state->src_w & 0xffff) * 15625) >> 
> > 10,
> > +                       new_plane_state->src_h >> 16,
> > +                       ((new_plane_state->src_h & 0xffff) * 15625) >> 
> > 10,
> > +                       new_plane_state->src_x >> 16,
> > +                       ((new_plane_state->src_x & 0xffff) * 15625) >> 
> > 10,
> > +                       new_plane_state->src_y >> 16,
> > +                       ((new_plane_state->src_y & 0xffff) * 15625) >> 
> > 10,
> > +                       fb->width, fb->height);
> > +            return -ENOSPC;
> > +        }
> >       }
> >       clips = __drm_plane_get_damage_clips(new_plane_state);
> > diff --git a/drivers/gpu/drm/drm_atomic_helper.c 
> > b/drivers/gpu/drm/drm_atomic_helper.c
> > index 8bf41aa24068..5a5ffa06b8bd 100644
> > --- a/drivers/gpu/drm/drm_atomic_helper.c
> > +++ b/drivers/gpu/drm/drm_atomic_helper.c
> > @@ -818,7 +818,7 @@ int drm_atomic_helper_check_plane_state(struct 
> > drm_plane_state *plane_state,
> >       *src = drm_plane_state_src(plane_state);
> >       *dst = drm_plane_state_dest(plane_state);
> > -    if (!fb) {
> > +    if (!fb && !plane_state->color_fill) {
> >           plane_state->visible = false;
> >           return 0;
> >       }
> > @@ -835,25 +835,31 @@ int drm_atomic_helper_check_plane_state(struct 
> > drm_plane_state *plane_state,
> >           return -EINVAL;
> >       }
> > -    drm_rect_rotate(src, fb->width << 16, fb->height << 16, rotation);
> > +    if (fb) {
> > +        drm_rect_rotate(src, fb->width << 16, fb->height << 16, 
> > rotation);
> > -    /* Check scaling */
> > -    hscale = drm_rect_calc_hscale(src, dst, min_scale, max_scale);
> > -    vscale = drm_rect_calc_vscale(src, dst, min_scale, max_scale);
> > -    if (hscale < 0 || vscale < 0) {
> > -        drm_dbg_kms(plane_state->plane->dev,
> > -                "Invalid scaling of plane\n");
> > -        drm_rect_debug_print("src: ", &plane_state->src, true);
> > -        drm_rect_debug_print("dst: ", &plane_state->dst, false);
> > -        return -ERANGE;
> > +        /* Check scaling */
> > +        hscale = drm_rect_calc_hscale(src, dst, min_scale, max_scale);
> > +        vscale = drm_rect_calc_vscale(src, dst, min_scale, max_scale);
> > +
> > +        if (hscale < 0 || vscale < 0) {
> > +            drm_dbg_kms(plane_state->plane->dev,
> > +                    "Invalid scaling of plane\n");
> > +            drm_rect_debug_print("src: ", &plane_state->src, true);
> > +            drm_rect_debug_print("dst: ", &plane_state->dst, false);
> > +            return -ERANGE;
> > +        }
> >       }
> >       if (crtc_state->enable)
> >           drm_mode_get_hv_timing(&crtc_state->mode, &clip.x2, &clip.y2);
> > -    plane_state->visible = drm_rect_clip_scaled(src, dst, &clip);
> > -
> > -    drm_rect_rotate_inv(src, fb->width << 16, fb->height << 16, 
> > rotation);
> > +    if (fb) {
> > +        plane_state->visible = drm_rect_clip_scaled(src, dst, &clip);
> > +        drm_rect_rotate_inv(src, fb->width << 16, fb->height << 16, 
> > rotation);
> > +    } else if (plane_state->color_fill) {
> > +        plane_state->visible = true;
> > +    }
> >       if (!plane_state->visible)
> >           /*
> > diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> > index 726f2f163c26..223b5ed93d3a 100644
> > --- a/drivers/gpu/drm/drm_plane.c
> > +++ b/drivers/gpu/drm/drm_plane.c
> > @@ -850,8 +850,8 @@ static int __setplane_internal(struct drm_plane 
> > *plane,
> >       WARN_ON(drm_drv_uses_atomic_modeset(plane->dev));
> > -    /* No fb means shut it down */
> > -    if (!fb) {
> > +    /* No fb and no color fill means shut it down */
> > +    if (!fb && (plane->state && !plane->state->color_fill)) {
>
> I'd suggest abstracting this to a helper function, which can then be 
> used in drm_atomic_plane_check() too.

Agreed.

> >           plane->old_fb = plane->fb;
> >           ret = plane->funcs->disable_plane(plane, ctx);
> >           if (!ret) {
> > @@ -902,8 +902,8 @@ static int __setplane_atomic(struct drm_plane *plane,
> >       WARN_ON(!drm_drv_uses_atomic_modeset(plane->dev));
> > -    /* No fb means shut it down */
> > -    if (!fb)
> > +    /* No fb and no color fill means shut it down */
> > +    if (!fb && (plane->state && !plane->state->color_fill))
> >           return plane->funcs->disable_plane(plane, ctx);
> >       /*
> > diff --git a/include/drm/drm_atomic_helper.h 
> > b/include/drm/drm_atomic_helper.h
> > index 2a0b17842402..aa7576f0879d 100644
> > --- a/include/drm/drm_atomic_helper.h
> > +++ b/include/drm/drm_atomic_helper.h
> > @@ -219,8 +219,9 @@ drm_atomic_plane_disabling(struct drm_plane_state 
> > *old_plane_state,
> >        * Anything else should be considered a bug in the atomic core, 
> > so we
> >        * gently warn about it.
> >        */
> > -    WARN_ON((new_plane_state->crtc == NULL && new_plane_state->fb != 
> > NULL) ||
> > -        (new_plane_state->crtc != NULL && new_plane_state->fb == NULL));
> > +    WARN_ON(!new_plane_state->color_fill &&
> > +            ((new_plane_state->crtc == NULL && new_plane_state->fb != 
> > NULL) ||
> > +            (new_plane_state->crtc != NULL && new_plane_state->fb == 
> > NULL)));
>
> Please fix the indentation.

Acked.

Thanks,

Jessica Zhang

> >       return old_plane_state->crtc && !new_plane_state->crtc;
> >   }
>
> --
> With best wishes
> Dmitry