[PATCH] drm/edid : calculate vsync and hsync from range limits block according to the EDID 1.4

[Daniel Vetter]

On Tue, May 03, 2016 at 11:05:25AM -0400, Vitaly Prosyak wrote:
> Do calculation of vsync and hsync from range limits
> EDID block according to the spec. EDID 1.4.
> 
> Signed-off-by: Vitaly Prosyak <vitaly.prosyak at amd.com>

Seems unrelated to the previous patch, please submit in a separate series.

> ---
>  drivers/gpu/drm/drm_edid.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 7e49962..601152b 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -1977,11 +1977,11 @@ mode_in_hsync_range(const struct drm_display_mode *mode,
>  	int hsync, hmin, hmax;
>  
>  	hmin = t[7];
> -	if (edid->revision >= 4)
> -	    hmin += ((t[4] & 0x04) ? 255 : 0);
> +	if (edid->revision >= 4 && ((t[4] & 0x0c) == 0x0c))
> +	    hmin += 255 ;
>  	hmax = t[8];
> -	if (edid->revision >= 4)
> -	    hmax += ((t[4] & 0x08) ? 255 : 0);
> +	if (edid->revision >= 4 && (t[4] & 0x08))
> +	    hmax += 255;

Please don't reshuffle code without functional changes. Same above, for
such small bugfixes it's best to only change what you need changed.

It might also be useful to introduce symbolic #defines for all these magic
constants.
-Daniel


>  	hsync = drm_mode_hsync(mode);
>  
>  	return (hsync <= hmax && hsync >= hmin);
> @@ -1994,11 +1994,11 @@ mode_in_vsync_range(const struct drm_display_mode *mode,
>  	int vsync, vmin, vmax;
>  
>  	vmin = t[5];
> -	if (edid->revision >= 4)
> -	    vmin += ((t[4] & 0x01) ? 255 : 0);
> +	if (edid->revision >= 4 && ((t[4] & 0x03) == 0x03))
> +	    vmin += 255;
>  	vmax = t[6];
> -	if (edid->revision >= 4)
> -	    vmax += ((t[4] & 0x02) ? 255 : 0);
> +	if (edid->revision >= 4 && (t[4] & 0x02))
> +	    vmax += 255;
>  	vsync = drm_mode_vrefresh(mode);
>  
>  	return (vsync <= vmax && vsync >= vmin);
> -- 
> 1.9.1
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch