Re: [PATCH v2 1/1] drm/mediatek: Fix errors when reporting rotation capability

["CK Hu (胡俊光)" <ck.hu@mediatek.com>]

Hi, Hsiao-chien:

On Mon, 2023-10-30 at 17:03 +0800, Hsiao Chien Sung wrote:
> For CRTCs that doesn't support rotation should still return
> DRM_MODE_ROTATE_0. Returns hardware capabilities accordingly.

The original code would not call drm_plane_create_rotation_property()
to create rotation property if CRTC does not support rotation. I think
this behavior is OK because not all drm driver call
drm_plane_create_rotation_property() and it works. So ovl adaptor is
not necessary to implement supported_rotations() callback function. If
some OVL does not support rotation, you could return 0 directly.

Regards,
CK

> 
> Fixes: 84d805753983 ("drm/mediatek: Support reflect-y plane
> rotation")
> 
> Reviewed-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@collabora.com>
> Signed-off-by: Hsiao Chien Sung <shawn.sung@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_drv.h       |  1 +
>  drivers/gpu/drm/mediatek/mtk_disp_ovl.c       | 30 ++++++++++-------
> --
>  .../gpu/drm/mediatek/mtk_disp_ovl_adaptor.c   |  5 ++++
>  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c   |  1 +
>  drivers/gpu/drm/mediatek/mtk_drm_plane.c      |  2 +-
>  5 files changed, 24 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> index 4d6e8b667bc3..c5afeb7c5527 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> @@ -127,6 +127,7 @@ void mtk_ovl_adaptor_register_vblank_cb(struct
> device *dev, void (*vblank_cb)(vo
>  void mtk_ovl_adaptor_unregister_vblank_cb(struct device *dev);
>  void mtk_ovl_adaptor_enable_vblank(struct device *dev);
>  void mtk_ovl_adaptor_disable_vblank(struct device *dev);
> +unsigned int mtk_ovl_adaptor_supported_rotations(struct device
> *dev);
>  void mtk_ovl_adaptor_start(struct device *dev);
>  void mtk_ovl_adaptor_stop(struct device *dev);
>  unsigned int mtk_ovl_adaptor_layer_nr(struct device *dev);
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> index ecc38932fd44..bca7b2f4b1d9 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> @@ -177,6 +177,7 @@ static const u32 mt8195_ovl_crc_ofs[] = {
>   * @supports_clrfmt_ext: whether the ovl supports clear format (for
> alpha blend)
>   * @crc_ofs: crc offset table
>   * @crc_cnt: count of crc registers (could be more than one bank)
> + * @rotations: supported rotations
>   */
>  struct mtk_disp_ovl_data {
>  	unsigned int addr;
> @@ -190,6 +191,7 @@ struct mtk_disp_ovl_data {
>  	bool supports_clrfmt_ext;
>  	const u32 *crc_ofs;
>  	size_t crc_cnt;
> +	unsigned int rotations;
>  };
>  
>  /**
> @@ -415,35 +417,26 @@ unsigned int mtk_ovl_layer_nr(struct device
> *dev)
>  
>  unsigned int mtk_ovl_supported_rotations(struct device *dev)
>  {
> -	return DRM_MODE_ROTATE_0 | DRM_MODE_ROTATE_180 |
> -	       DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y;
> +	struct mtk_disp_ovl *ovl = dev_get_drvdata(dev);
> +
> +	return ovl->data->rotations ?: DRM_MODE_ROTATE_0;
>  }
>  
>  int mtk_ovl_layer_check(struct device *dev, unsigned int idx,
>  			struct mtk_plane_state *mtk_state)
>  {
>  	struct drm_plane_state *state = &mtk_state->base;
> -	unsigned int rotation = 0;
>  
> -	rotation = drm_rotation_simplify(state->rotation,
> -					 DRM_MODE_ROTATE_0 |
> -					 DRM_MODE_REFLECT_X |
> -					 DRM_MODE_REFLECT_Y);
> -	rotation &= ~DRM_MODE_ROTATE_0;
> -
> -	/* We can only do reflection, not rotation */
> -	if ((rotation & DRM_MODE_ROTATE_MASK) != 0)
> +	if (state->rotation & ~mtk_ovl_supported_rotations(dev))
>  		return -EINVAL;
>  
>  	/*
>  	 * TODO: Rotating/reflecting YUV buffers is not supported at
> this time.
>  	 *	 Only RGB[AX] variants are supported.
>  	 */
> -	if (state->fb->format->is_yuv && rotation != 0)
> +	if (state->fb->format->is_yuv && (state->rotation &
> ~DRM_MODE_ROTATE_0))
>  		return -EINVAL;
>  
> -	state->rotation = rotation;
> -
>  	return 0;
>  }
>  
> @@ -883,6 +876,15 @@ static const struct mtk_disp_ovl_data
> mt8195_ovl_driver_data = {
>  	.supports_clrfmt_ext = true,
>  	.crc_ofs = mt8195_ovl_crc_ofs,
>  	.crc_cnt = ARRAY_SIZE(mt8195_ovl_crc_ofs),
> +
> +	/*
> +	 * although OVL only supports reflections on MT8195,
> +	 * reflect x + reflect y = rotate 180
> +	 */
> +	.rotations = DRM_MODE_ROTATE_0   |
> +		     DRM_MODE_ROTATE_180 |
> +		     DRM_MODE_REFLECT_X  |
> +		     DRM_MODE_REFLECT_Y,
>  };
>  
>  static const struct of_device_id mtk_disp_ovl_driver_dt_match[] = {
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
> b/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
> index 4398db9a6276..b0d3ebdba93a 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
> @@ -383,6 +383,11 @@ void mtk_ovl_adaptor_register_vblank_cb(struct
> device *dev, void (*vblank_cb)(vo
>  				     vblank_cb, vblank_cb_data);
>  }
>  
> +unsigned int mtk_ovl_adaptor_supported_rotations(struct device *dev)
> +{
> +	return DRM_MODE_ROTATE_0;
> +}
> +
>  void mtk_ovl_adaptor_unregister_vblank_cb(struct device *dev)
>  {
>  	struct mtk_disp_ovl_adaptor *ovl_adaptor =
> dev_get_drvdata(dev);
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> index ffa4868b1222..206dd6f6f99e 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> @@ -422,6 +422,7 @@ static const struct mtk_ddp_comp_funcs
> ddp_ovl_adaptor = {
>  	.remove = mtk_ovl_adaptor_remove_comp,
>  	.get_formats = mtk_ovl_adaptor_get_formats,
>  	.get_num_formats = mtk_ovl_adaptor_get_num_formats,
> +	.supported_rotations = mtk_ovl_adaptor_supported_rotations,
>  };
>  
>  static const char * const mtk_ddp_comp_stem[MTK_DDP_COMP_TYPE_MAX] =
> {
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> index e2ec61b69618..894c39a38a58 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> @@ -344,7 +344,7 @@ int mtk_plane_init(struct drm_device *dev, struct
> drm_plane *plane,
>  		return err;
>  	}
>  
> -	if (supported_rotations & ~DRM_MODE_ROTATE_0) {
> +	if (supported_rotations) {
>  		err = drm_plane_create_rotation_property(plane,
>  							 DRM_MODE_ROTAT
> E_0,
>  							 supported_rota
> tions);