Re: [PATCH RFC v6 07/10] drm/atomic: Loosen FB atomic checks

Dmitry Baryshkov
2023-09-24T10:20:06Z

On 29/08/2023 03:05, Jessica Zhang wrote:
> Loosen the requirements for atomic and legacy commit so that, in cases
> where pixel_source != FB, the commit can still go through.
>
> This includes adding framebuffer NULL checks in other areas to account for
> FB being NULL when non-FB pixel sources are enabled.
>
> To disable a plane, the pixel_source must be NONE or the FB must be NULL
> if pixel_source == FB.
>
> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
> ---
> drivers/gpu/drm/drm_atomic.c | 20 +++++++++++---------
> drivers/gpu/drm/drm_atomic_helper.c | 36 ++++++++++++++++++++----------------
> include/drm/drm_atomic_helper.h | 4 ++--
> include/drm/drm_plane.h | 29 +++++++++++++++++++++++++++++
> 4 files changed, 62 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index cc0e93d19e15..cdc6cfedd433 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;
> }
>
> @@ -706,9 +706,11 @@ static int drm_atomic_plane_check(const struct drm_plane_state *old_plane_state,
> }
>
>
> - ret = drm_atomic_plane_check_fb(new_plane_state);
> - if (ret)
> - return ret;
> + if (new_plane_state->pixel_source == DRM_PLANE_PIXEL_SOURCE_FB && fb) {

Nit: could you please be more specific here? Drop the fb variable and
use new_plane_state->fb directly.

> + ret = drm_atomic_plane_check_fb(new_plane_state);
> + if (ret)
> + return ret;
> + }
>
> if (plane_switching_crtc(old_plane_state, new_plane_state)) {
> drm_dbg_atomic(plane->dev,
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index 41b8066f61ff..a176064ee27e 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 +881,29 @@ 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) {

And here too. Could you please move fb var into the condition?

Other than that LGTM

> + 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 (crtc_state->enable)
> - drm_mode_get_hv_timing(&crtc_state->mode, &clip.x2, &clip.y2);
> + 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;
> + }
>
> - plane_state->visible = drm_rect_clip_scaled(src, dst, &clip);
> + if (crtc_state->enable)
> + drm_mode_get_hv_timing(&crtc_state->mode, &clip.x2, &clip.y2);
>
> - drm_rect_rotate_inv(src, fb->width << 16, fb->height << 16, rotation);
> + 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/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 a58f84b6bd5e..4c5b7bcdb25c 100644
> --- a/include/drm/drm_plane.h
> +++ b/include/drm/drm_plane.h
> @@ -992,6 +992,35 @@ 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_SOLID_FILL && 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_NONE:
> + return false;
> + case DRM_PLANE_PIXEL_SOURCE_SOLID_FILL:
> + return state->solid_fill_blob != NULL;
> + case DRM_PLANE_PIXEL_SOURCE_FB:
> + default:
> + WARN_ON(state->pixel_source != DRM_PLANE_PIXEL_SOURCE_FB);
> + }
> +
> + return state->fb != NULL;
> +}
> +
> bool drm_any_plane_has_format(struct drm_device *dev,
> u32 format, u64 modifier);
>
>

--
With best wishes
Dmitry