drm/mediatek: only announce AFBC if really supported

Currently even the SoC's OVL does not declare the support of AFBC, AFBC
is still announced to the userspace within the IN_FORMATS blob, which
breaks modern Wayland compositors like KWin Wayland and others.

Gate passing modifiers to drm_universal_plane_init() behind querying the
driver of the hardware block for AFBC support.

Fixes: c410fa9b07 ("drm/mediatek: Add AFBC support to Mediatek DRM driver")
Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
Reviewed-by: CK Hu <ck.hu@medaitek.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20250531121140.387661-1-uwu@icenowy.me/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

drivers/gpu/drm/mediatek/mtk_crtc.c

@@ -963,7 +963,8 @@ static int mtk_crtc_init_comp_planes(struct drm_device *drm_dev,
 				mtk_ddp_comp_supported_rotations(comp),
 				mtk_ddp_comp_get_blend_modes(comp),
 				mtk_ddp_comp_get_formats(comp),
-				mtk_ddp_comp_get_num_formats(comp), i);
+				mtk_ddp_comp_get_num_formats(comp),
+				mtk_ddp_comp_is_afbc_supported(comp), i);
 		if (ret)
 			return ret;
 

drivers/gpu/drm/mediatek/mtk_ddp_comp.c

@@ -366,6 +366,7 @@ static const struct mtk_ddp_comp_funcs ddp_ovl = {
 	.get_blend_modes = mtk_ovl_get_blend_modes,
 	.get_formats = mtk_ovl_get_formats,
 	.get_num_formats = mtk_ovl_get_num_formats,
+	.is_afbc_supported = mtk_ovl_is_afbc_supported,
 };
 
 static const struct mtk_ddp_comp_funcs ddp_postmask = {

drivers/gpu/drm/mediatek/mtk_ddp_comp.h

@@ -83,6 +83,7 @@ struct mtk_ddp_comp_funcs {
 	u32 (*get_blend_modes)(struct device *dev);
 	const u32 *(*get_formats)(struct device *dev);
 	size_t (*get_num_formats)(struct device *dev);
+	bool (*is_afbc_supported)(struct device *dev);
 	void (*connect)(struct device *dev, struct device *mmsys_dev, unsigned int next);
 	void (*disconnect)(struct device *dev, struct device *mmsys_dev, unsigned int next);
 	void (*add)(struct device *dev, struct mtk_mutex *mutex);
@@ -294,6 +295,14 @@ size_t mtk_ddp_comp_get_num_formats(struct mtk_ddp_comp *comp)
 	return 0;
 }
 
+static inline bool mtk_ddp_comp_is_afbc_supported(struct mtk_ddp_comp *comp)
+{
+	if (comp->funcs && comp->funcs->is_afbc_supported)
+		return comp->funcs->is_afbc_supported(comp->dev);
+
+	return false;
+}
+
 static inline bool mtk_ddp_comp_add(struct mtk_ddp_comp *comp, struct mtk_mutex *mutex)
 {
 	if (comp->funcs && comp->funcs->add) {

drivers/gpu/drm/mediatek/mtk_disp_drv.h

@@ -106,6 +106,7 @@ void mtk_ovl_disable_vblank(struct device *dev);
 u32 mtk_ovl_get_blend_modes(struct device *dev);
 const u32 *mtk_ovl_get_formats(struct device *dev);
 size_t mtk_ovl_get_num_formats(struct device *dev);
+bool mtk_ovl_is_afbc_supported(struct device *dev);
 
 void mtk_ovl_adaptor_add_comp(struct device *dev, struct mtk_mutex *mutex);
 void mtk_ovl_adaptor_remove_comp(struct device *dev, struct mtk_mutex *mutex);

drivers/gpu/drm/mediatek/mtk_disp_ovl.c

@@ -236,6 +236,13 @@ size_t mtk_ovl_get_num_formats(struct device *dev)
 	return ovl->data->num_formats;
 }
 
+bool mtk_ovl_is_afbc_supported(struct device *dev)
+{
+	struct mtk_disp_ovl *ovl = dev_get_drvdata(dev);
+
+	return ovl->data->supports_afbc;
+}
+
 int mtk_ovl_clk_enable(struct device *dev)
 {
 	struct mtk_disp_ovl *ovl = dev_get_drvdata(dev);

drivers/gpu/drm/mediatek/mtk_plane.c

@@ -326,7 +326,8 @@ static const struct drm_plane_helper_funcs mtk_plane_helper_funcs = {
 int mtk_plane_init(struct drm_device *dev, struct drm_plane *plane,
 		   unsigned long possible_crtcs, enum drm_plane_type type,
 		   unsigned int supported_rotations, const u32 blend_modes,
-		   const u32 *formats, size_t num_formats, unsigned int plane_idx)
+		   const u32 *formats, size_t num_formats,
+		   bool supports_afbc, unsigned int plane_idx)
 {
 	int err;
 
@@ -337,7 +338,9 @@ int mtk_plane_init(struct drm_device *dev, struct drm_plane *plane,
 
 	err = drm_universal_plane_init(dev, plane, possible_crtcs,
 				       &mtk_plane_funcs, formats,
-				       num_formats, modifiers, type, NULL);
+				       num_formats,
+				       supports_afbc ? modifiers : NULL,
+				       type, NULL);
 	if (err) {
 		DRM_ERROR("failed to initialize plane\n");
 		return err;

drivers/gpu/drm/mediatek/mtk_plane.h

@@ -49,5 +49,6 @@ to_mtk_plane_state(struct drm_plane_state *state)
 int mtk_plane_init(struct drm_device *dev, struct drm_plane *plane,
 		   unsigned long possible_crtcs, enum drm_plane_type type,
 		   unsigned int supported_rotations, const u32 blend_modes,
-		   const u32 *formats, size_t num_formats, unsigned int plane_idx);
+		   const u32 *formats, size_t num_formats,
+		   bool supports_afbc, unsigned int plane_idx);
 #endif