Re: [PATCH v2 1/4] drm/exynos: fb: use drm_format_num_planes to get buffer count

[Joonyoung Shim <jy0922.shim@samsung.com>]

Hi Tobias,

On 04/28/2015 06:10 AM, Tobias Jakobi wrote:
> The previous code had some special case handling for the buffer
> count in exynos_drm_format_num_buffers().
> 
> This code was incorrect though, since this special case doesn't
> exist for DRM. It stemmed from the existence of the special NV12M
> V4L2 format. NV12 is a bi-planar format (separate planes for luma
> and chroma) and V4L2 differentiates between a NV12 buffer where
> luma and chroma is contiguous in memory (so no data between
> luma/chroma), and a NV12 buffer where luma and chroma have two
> explicit memory locations (which is then called NV12M).
> 
> This distinction doesn't exist for DRM. A bi-planar format always
> explicitly comes with the information about its two planes (even
> if these planes should be contiguous).
> 
> Signed-off-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
> ---
>  drivers/gpu/drm/exynos/exynos_drm_fb.c | 39 +---------------------------------
>  1 file changed, 1 insertion(+), 38 deletions(-)
> 

Looks good to me about this series,

Acked-by: Joonyoung Shim <jy0922.shim@samsung.com>

Thanks.

> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fb.c b/drivers/gpu/drm/exynos/exynos_drm_fb.c
> index 929cb03..142eb4e 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fb.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fb.c
> @@ -171,43 +171,6 @@ exynos_drm_framebuffer_init(struct drm_device *dev,
>  	return &exynos_fb->fb;
>  }
>  
> -static u32 exynos_drm_format_num_buffers(struct drm_mode_fb_cmd2 *mode_cmd)
> -{
> -	unsigned int cnt = 0;
> -
> -	if (mode_cmd->pixel_format != DRM_FORMAT_NV12)
> -		return drm_format_num_planes(mode_cmd->pixel_format);
> -
> -	while (cnt != MAX_FB_BUFFER) {
> -		if (!mode_cmd->handles[cnt])
> -			break;
> -		cnt++;
> -	}
> -
> -	/*
> -	 * check if NV12 or NV12M.
> -	 *
> -	 * NV12
> -	 * handles[0] = base1, offsets[0] = 0
> -	 * handles[1] = base1, offsets[1] = Y_size
> -	 *
> -	 * NV12M
> -	 * handles[0] = base1, offsets[0] = 0
> -	 * handles[1] = base2, offsets[1] = 0
> -	 */
> -	if (cnt == 2) {
> -		/*
> -		 * in case of NV12 format, offsets[1] is not 0 and
> -		 * handles[0] is same as handles[1].
> -		 */
> -		if (mode_cmd->offsets[1] &&
> -			mode_cmd->handles[0] == mode_cmd->handles[1])
> -			cnt = 1;
> -	}
> -
> -	return cnt;
> -}
> -
>  static struct drm_framebuffer *
>  exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
>  		      struct drm_mode_fb_cmd2 *mode_cmd)
> @@ -230,7 +193,7 @@ exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
>  
>  	drm_helper_mode_fill_fb_struct(&exynos_fb->fb, mode_cmd);
>  	exynos_fb->exynos_gem_obj[0] = to_exynos_gem_obj(obj);
> -	exynos_fb->buf_cnt = exynos_drm_format_num_buffers(mode_cmd);
> +	exynos_fb->buf_cnt = drm_format_num_planes(mode_cmd->pixel_format);
>  
>  	DRM_DEBUG_KMS("buf_cnt = %d\n", exynos_fb->buf_cnt);
>  
>