Re: [PATCH v4 05/17] drm/mediatek: Set DRM mode configs accordingly

["CK Hu (胡俊光)" <ck.hu@mediatek.com>]

Hi, Hsiao-chien:

On Tue, 2023-12-12 at 20:19 +0800, Hsiao Chien Sung wrote:
> Set DRM mode configs limitation accroding to the
> hardware capabilities.
> 
> Signed-off-by: Hsiao Chien Sung <shawn.sung@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_drv.c | 28 ++++++++++++++++++----
> ----
>  drivers/gpu/drm/mediatek/mtk_drm_drv.h |  1 +
>  2 files changed, 21 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> index 5d551bff6b3f..a4b740420ebb 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> @@ -304,6 +304,7 @@ static const struct mtk_mmsys_driver_data
> mt8188_vdosys0_driver_data = {
>  	.conn_routes = mt8188_mtk_ddp_main_routes,
>  	.conn_routes_num = ARRAY_SIZE(mt8188_mtk_ddp_main_routes),
>  	.mmsys_dev_num = 2,
> +	.max_pitch = GENMASK(15, 0),
>  };
>  
>  static const struct mtk_mmsys_driver_data mt8192_mmsys_driver_data =
> {
> @@ -318,6 +319,7 @@ static const struct mtk_mmsys_driver_data
> mt8195_vdosys0_driver_data = {
>  	.main_path = mt8195_mtk_ddp_main,
>  	.main_len = ARRAY_SIZE(mt8195_mtk_ddp_main),
>  	.mmsys_dev_num = 2,
> +	.max_pitch = GENMASK(15, 0),
>  };
>  
>  static const struct mtk_mmsys_driver_data mt8195_vdosys1_driver_data
> = {
> @@ -325,6 +327,7 @@ static const struct mtk_mmsys_driver_data
> mt8195_vdosys1_driver_data = {
>  	.ext_len = ARRAY_SIZE(mt8195_mtk_ddp_ext),
>  	.mmsys_id = 1,
>  	.mmsys_dev_num = 2,
> +	.max_pitch = GENMASK(15, 0),
>  };
>  
>  static const struct of_device_id mtk_drm_of_ids[] = {
> @@ -463,16 +466,16 @@ static int mtk_drm_kms_init(struct drm_device
> *drm)
>  	if (ret)
>  		goto put_mutex_dev;
>  
> -	drm->mode_config.min_width = 64;
> -	drm->mode_config.min_height = 64;
> -
>  	/*
> -	 * set max width and height as default value(4096x4096).
> -	 * this value would be used to check framebuffer size
> limitation
> -	 * at drm_mode_addfb().
> +	 * Set default values for drm mode config
> +	 * these values will be referenced by drm_mode_addfb() as
> +	 * frame buffer size limitation.
>  	 */
> -	drm->mode_config.max_width = 4096;
> -	drm->mode_config.max_height = 4096;
> +	drm->mode_config.min_width = 1;
> +	drm->mode_config.min_height = 1;
> +	drm->mode_config.cursor_width = 512;
> +	drm->mode_config.cursor_height = 512;

Why do you change other SoC's min_width/min_height and
cursor_width/cursor_height? Describe the reason.

Regards,
CK

> +
>  	drm->mode_config.funcs = &mtk_drm_mode_config_funcs;
>  	drm->mode_config.helper_private = &mtk_drm_mode_config_helpers;
>  
> @@ -502,6 +505,15 @@ static int mtk_drm_kms_init(struct drm_device
> *drm)
>  		for (j = 0; j < private->data->mmsys_dev_num; j++) {
>  			priv_n = private->all_drm_private[j];
>  
> +			if (priv_n->data->max_pitch) {
> +				/* Save 4 bytes for the color depth
> (pitch = width x bpp) */
> +				drm->mode_config.max_width  = priv_n-
> >data->max_pitch >> 2;
> +				drm->mode_config.max_height = priv_n-
> >data->max_pitch >> 2;
> +			} else {
> +				drm->mode_config.max_width = 4096;
> +				drm->mode_config.max_height = 4096;
> +			}
> +
>  			if (i == 0 && priv_n->data->main_len) {
>  				ret = mtk_drm_crtc_create(drm, priv_n-
> >data->main_path,
>  							  priv_n->data-
> >main_len, j,
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> index d2efd715699f..3d6c1f58a7ec 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> @@ -41,6 +41,7 @@ struct mtk_mmsys_driver_data {
>  	bool shadow_register;
>  	unsigned int mmsys_id;
>  	unsigned int mmsys_dev_num;
> +	u32 max_pitch;
>  };
>  
>  struct mtk_drm_private {