[Intel-gfx] [PATCH 18/22] drm/i915: Make sure fb offset is (macro)pixel aligned

[Daniel Vetter]

On Wed, Oct 14, 2015 at 07:29:10PM +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> We convert the fb->offsets[] into x/y offsets, so they must be
> (macro)pixel aligned.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 36 +++++++++++++++++++++++++++++++++---
>  1 file changed, 33 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index ce346cfe..70e6e27 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -14284,6 +14284,36 @@ u32 intel_fb_pitch_limit(struct drm_device *dev, uint64_t fb_modifier,
>  	}
>  }
>  
> +static int intel_fb_check_offsets(const struct drm_mode_fb_cmd2 *mode_cmd)
> +{
> +	uint32_t format = mode_cmd->pixel_format;
> +	int i;
> +
> +	for (i = 0; i < drm_format_num_planes(format); i++) {
> +		unsigned int cpp;
> +
> +		switch (format) {
> +		case DRM_FORMAT_YUYV:
> +		case DRM_FORMAT_UYVY:
> +		case DRM_FORMAT_YVYU:
> +		case DRM_FORMAT_VYUY:
> +			cpp = 4;
> +			break;
> +		default:
> +			cpp = drm_format_plane_cpp(format, i);
> +			break;

Might be worth it to extract this into a drm helper. gallium also has the
concept of a pixel block size, and it's _really_ nice imo.
-Daniel

> +		}
> +
> +		if (mode_cmd->offsets[i] % cpp) {
> +			DRM_DEBUG("fb plane %d offset 0x%08x not (macro)pixel aligned\n",
> +				  i, mode_cmd->offsets[i]);
> +			return -EINVAL;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
>  static int intel_framebuffer_init(struct drm_device *dev,
>  				  struct intel_framebuffer *intel_fb,
>  				  struct drm_mode_fb_cmd2 *mode_cmd,
> @@ -14410,9 +14440,9 @@ static int intel_framebuffer_init(struct drm_device *dev,
>  		return -EINVAL;
>  	}
>  
> -	/* FIXME need to adjust LINOFF/TILEOFF accordingly. */
> -	if (mode_cmd->offsets[0] != 0)
> -		return -EINVAL;
> +	ret = intel_fb_check_offsets(mode_cmd);
> +	if (ret)
> +		return ret;
>  
>  	aligned_height = intel_fb_align_height(dev, mode_cmd->height,
>  					       mode_cmd->pixel_format,
> -- 
> 2.4.9
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch