[PATCH] drm/mediatek: only announce AFBC if really supported
Chun-Kuang Hu
chunkuang.hu at kernel.org
Wed Jun 25 15:13:43 UTC 2025
Hi, Icenowy:
Icenowy Zheng <uwu at icenowy.me> 於 2025年5月31日 週六 下午8:12寫道：
>
> 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.
Applied to mediatek-drm-fixes [1], thanks.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-fixes
Regards,
Chun-Kuang.
>
> Fixes: c410fa9b07c3 ("drm/mediatek: Add AFBC support to Mediatek DRM driver")
> Signed-off-by: Icenowy Zheng <uwu at icenowy.me>
> ---
> Patch tested on MT8183, on which KWin Wayland 5.27.12 is fixed.
>
> In addition, I tried to fake supports_afbc in mt8183_ovl_driver_data and
> mt8183_ovl_2l_driver_data, then KWin Wayland gets broken again and
> modetest also shows the AFBC modifier in IN_FORMATS.
>
> drivers/gpu/drm/mediatek/mtk_crtc.c | 3 ++-
> drivers/gpu/drm/mediatek/mtk_ddp_comp.c | 1 +
> drivers/gpu/drm/mediatek/mtk_ddp_comp.h | 9 +++++++++
> drivers/gpu/drm/mediatek/mtk_disp_drv.h | 1 +
> drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 7 +++++++
> drivers/gpu/drm/mediatek/mtk_plane.c | 7 +++++--
> drivers/gpu/drm/mediatek/mtk_plane.h | 3 ++-
> 7 files changed, 27 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_crtc.c b/drivers/gpu/drm/mediatek/mtk_crtc.c
> index 8f6fba4217ece..53359c2465b65 100644
> --- a/drivers/gpu/drm/mediatek/mtk_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_crtc.c
> @@ -930,7 +930,8 @@ 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;
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_ddp_comp.c
> index edc6417639e64..ac6620e10262e 100644
> --- a/drivers/gpu/drm/mediatek/mtk_ddp_comp.c
> +++ b/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 = {
> diff --git a/drivers/gpu/drm/mediatek/mtk_ddp_comp.h b/drivers/gpu/drm/mediatek/mtk_ddp_comp.h
> index 39720b27f4e9e..7289b3dcf22f2 100644
> --- a/drivers/gpu/drm/mediatek/mtk_ddp_comp.h
> +++ b/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) {
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> index 04217a36939cd..679d413bf10be 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> +++ b/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);
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> index d0581c4e3c999..e0236353d4997 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> +++ b/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);
> diff --git a/drivers/gpu/drm/mediatek/mtk_plane.c b/drivers/gpu/drm/mediatek/mtk_plane.c
> index 655106bbb76d3..e08b771bc25e9 100644
> --- a/drivers/gpu/drm/mediatek/mtk_plane.c
> +++ b/drivers/gpu/drm/mediatek/mtk_plane.c
> @@ -321,7 +321,8 @@ 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;
>
> @@ -332,7 +333,9 @@ 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;
> diff --git a/drivers/gpu/drm/mediatek/mtk_plane.h b/drivers/gpu/drm/mediatek/mtk_plane.h
> index 3b13b89989c7e..95c5fa5295d8a 100644
> --- a/drivers/gpu/drm/mediatek/mtk_plane.h
> +++ b/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
> --
> 2.49.0
>
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