Re: [PATCH RFC v4 4/7] drm/atomic: Loosen FB atomic checks

Dmitry Baryshkov
2023-06-30T00:49:36Z

On 30/06/2023 03:25, Jessica Zhang wrote:
> Loosen the requirements for atomic and legacy commit so that, in cases
> where solid fill planes is enabled but no FB is set, the commit can
> still go through.
>
> This includes adding framebuffer NULL checks in other areas to account
> for FB being NULL when solid fill is enabled.
>
> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
> ---
> drivers/gpu/drm/drm_atomic.c | 14 +++++++-------
> drivers/gpu/drm/drm_atomic_helper.c | 34 ++++++++++++++++++++--------------
> drivers/gpu/drm/drm_plane.c | 8 ++++----
> include/drm/drm_atomic_helper.h | 4 ++--
> include/drm/drm_plane.h | 28 ++++++++++++++++++++++++++++
> 5 files changed, 61 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index 404b984d2d9f..ec9681c25366 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -668,14 +668,14 @@ static int drm_atomic_plane_check(const struct drm_plane_state *old_plane_state,
> const struct drm_framebuffer *fb = new_plane_state->fb;
> int ret;
>
> - /* either *both* CRTC and FB must be set, or neither */
> - if (crtc && !fb) {
> - drm_dbg_atomic(plane->dev, "[PLANE:%d:%s] CRTC set but no FB\n",
> + /* either *both* CRTC and pixel source must be set, or neither */
> + if (crtc && !drm_plane_has_visible_data(new_plane_state)) {
> + drm_dbg_atomic(plane->dev, "[PLANE:%d:%s] CRTC set but no visible data\n",
> plane->base.id, plane->name);
> return -EINVAL;
> - } else if (fb && !crtc) {
> - drm_dbg_atomic(plane->dev, "[PLANE:%d:%s] FB set but no CRTC\n",
> - plane->base.id, plane->name);
> + } else if (drm_plane_has_visible_data(new_plane_state) && !crtc) {
> + drm_dbg_atomic(plane->dev, "[PLANE:%d:%s] Source %d has visible data but no CRTC\n",
> + plane->base.id, plane->name, new_plane_state->pixel_source);
> return -EINVAL;
> }
>
> @@ -706,7 +706,7 @@ static int drm_atomic_plane_check(const struct drm_plane_state *old_plane_state,
> }
>
>
> - if (fb) {
> + if (new_plane_state->pixel_source == DRM_PLANE_PIXEL_SOURCE_FB && fb) {
> ret = drm_atomic_check_fb(new_plane_state);
> if (ret)
> return ret;
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index 41b8066f61ff..d05ec9ef2b3e 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -864,7 +864,7 @@ 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 (!drm_plane_has_visible_data(plane_state)) {
> plane_state->visible = false;
> return 0;
> }
> @@ -881,25 +881,31 @@ 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 (plane_state->pixel_source == DRM_PLANE_PIXEL_SOURCE_FB && 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 (plane_state->pixel_source == DRM_PLANE_PIXEL_SOURCE_FB && 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 (drm_plane_solid_fill_enabled(plane_state)) {
> + 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 24e7998d1731..5f19a27ba182 100644
> --- a/drivers/gpu/drm/drm_plane.c
> +++ b/drivers/gpu/drm/drm_plane.c
> @@ -861,8 +861,8 @@ 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 visible data means shut it down */
> + if (!drm_plane_has_visible_data(plane->state)) {
> plane->old_fb = plane->fb;
> ret = plane->funcs->disable_plane(plane, ctx);
> if (!ret) {
> @@ -913,8 +913,8 @@ 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 visible data means shut it down */
> + if (!drm_plane_has_visible_data(plane->state))
> return plane->funcs->disable_plane(plane, ctx);
>
> /*
> diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
> index 536a0b0091c3..6d97f38ac1f6 100644
> --- a/include/drm/drm_atomic_helper.h
> +++ b/include/drm/drm_atomic_helper.h
> @@ -256,8 +256,8 @@ 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->crtc == NULL && drm_plane_has_visible_data(new_plane_state)) ||
> + (new_plane_state->crtc != NULL && !drm_plane_has_visible_data(new_plane_state)));
>
> return old_plane_state->crtc && !new_plane_state->crtc;
> }
> diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
> index 73fb6cf8a5d9..f893f7a56912 100644
> --- a/include/drm/drm_plane.h
> +++ b/include/drm/drm_plane.h
> @@ -998,6 +998,34 @@ static inline struct drm_plane *drm_plane_find(struct drm_device *dev,
> #define drm_for_each_plane(plane, dev) \
> list_for_each_entry(plane, &(dev)->mode_config.plane_list, head)
>
> +/**
> + * drm_plane_solid_fill_enabled - Check if solid fill is enabled on plane
> + * @state: plane state
> + *
> + * Returns:
> + * Whether the plane has been assigned a solid_fill_blob
> + */
> +static inline bool drm_plane_solid_fill_enabled(struct drm_plane_state *state)
> +{
> + if (!state)
> + return false;
> + return state->pixel_source == DRM_PLANE_PIXEL_SOURCE_COLOR && state->solid_fill_blob;
> +}
> +
> +static inline bool drm_plane_has_visible_data(const struct drm_plane_state *state)
> +{
> + switch (state->pixel_source) {
> + case DRM_PLANE_PIXEL_SOURCE_COLOR:
> + return state->solid_fill_blob != NULL;
> +
> + default:

I'd say, there should a WARN_ON for the default case and then
fallthrough to the FB case.

> + return state->fb != NULL;
> + }
> +
> + return false;
> +}
> +
> +
> bool drm_any_plane_has_format(struct drm_device *dev,
> u32 format, u64 modifier);
>
>

--
With best wishes
Dmitry