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

From: Dmitry Baryshkov
Date: Sun Sep 24 2023 - 06:20:08 EST

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@xxxxxxxxxxx>
---
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