[PATCH] drm/edid: Add both 60Hz and 59.94Hz CEA modes to connector's mode list

[Andy Furniss]

ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> Having both modes can be beneficial for video playback cases. If you can
> match the video framerate exactly, and the audio and video clocks come
> from the same source, you should be able to avoid dropped/repeated
> frames without expensive operations such as resampling the audio to
> match video output rate.
>
> Rather than add both variants based on the CEA extension short video
> descriptors in do_cea_modes(), add only one variant there. Once all
> the EDID has been fully probed, do a loop over the entire probed mode
> list, during which we add the other variants for all modes that match
> CEA modes. This allows us to match modes that didn't come via the CEA
> short video descriptors. For example one Samsung TV here doesn't have
> the 640x480-60 mode as a SVD, but instead it's specified via a detailed
> timing descriptor.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
> A few people requested this. Originally I was a bit opposed to it, but
> when I thought about it a bit more I figured if the audio and video
> clocks come from the same source (or happen to be close enough w/o
> significant drift), this could provide a better A/V sync w/o resampling
> tricks.

I see this has gone in now, one thing I notice is that xorg/apps/xrandr 
only prints Hz to 1dp so you can't see which mode is which for the 24p 
and 30i cases.

Maybe someone reading has commit access for xorg?