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

Andy Furniss adf.lists at gmail.com
Tue Jun 18 03:36:50 PDT 2013


Ville Syrjälä wrote:
> On Tue, Jun 18, 2013 at 11:10:30AM +0100, Andy Furniss wrote:
>> 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?
>
> Not sure if you noticed but I posted some relevant xrandr patches to
> xorg-devel. Unfortunately I got no response, and I've been too lazy
> to figure out who I need to pester.
>

Ahh, sorry I didn't see those, I just has a look at the current code to 
check it was still the same.



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