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

[Prosyak, Vitaly]

Reduce the image size.

Yes, this is unrelated to the previous patch, but for the  coding  it is important to have same style for range limit EIDD block.
I mean the following: for calculation  if mode is in range one style ,but for ranges retrieval another style.
I am proposing to follow the style which looks to me closer to the spec.

I have attached the screenshot demonstrates those magic numbers.
Vitaly

-----Original Message-----
From: Daniel Vetter [mailto:daniel.vetter at ffwll.ch] On Behalf Of Daniel Vetter
Sent: Tuesday, May 03, 2016 4:26 PM
To: Prosyak, Vitaly
Cc: dri-devel at lists.freedesktop.org
Subject: Re: [PATCH] drm/edid : calculate vsync and hsync from range limits block according to the EDID 1.4

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
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
-------------- next part --------------
A non-text attachment was scrubbed...
Name: range_limits_1.4_edid_block.JPG
Type: image/jpeg
Size: 177026 bytes
Desc: range_limits_1.4_edid_block.JPG
URL: <https://lists.freedesktop.org/archives/dri-devel/attachments/20160504/bb90e41a/attachment-0001.jpe>