[Openchrome-devel] VX800 TMDS support

[Xavier Bachelot]

Auke Schrijnen wrote:
>> Hi Auke,
>>
>> Here's a small patch that may enable DVI output on your M700. Please
> give it a try.
>> Regards,
>> Xavier
> 
> Xavier, Tim,
> 
> Here are the logs and config files from my attempts to get DVI output
> working on my Epia M700 (VX800) board connected to my Sony Bravia 40W2000
> TV using a DVI to HDMI cable. I don't know if PAL and NTSC are an issue
> with HDMI, but it is a European model so it should use a PAL system.
>
No, NTSC/PAL are from the last century ;-) It's being superseded by the 
HD modes, which are an international standard.

> The first try was without any options. This result in a distorted screen
> (you can see some colours from the Ubuntu login screen, but it's
> 'waving'). The resolution is 800x600 (according to the logs), but my tv
> reports 480p.
> 
This try doesn't activate the DFP output, the driver selects the CRT 
output so no wonders here it is not working. The solution to this would 
probably be to sense both the CRT port and the DFP port and only enable 
the ones with something connected to them (properly displaying on 
multiple outputs would also need dual head to be implemented, which is 
not done yet and is a different matter anyway).
At least, the DFP port should have a higher priority than the CRT port, 
just like the LCD port does have a higher priority than the CRT port.

> The second try was with option "ActiveDevice" "DFP". This results in a
> blank screen (black, or 'no signal'). This is also the case with the third
> try where i added a Modeline (found in the mythtv wiki).
>
The EDID from the TV is not collected thru the DFP port, so the driver 
doesn't know how to set the HorizSync and VertRefresh value for the TV, 
neither does it get the supported modes.

> The fourth try was adding HorizSync and VertRefresh (that was needed when
> i was using the vga output before) which result in a nice clean FullHD
> 1920x1080 screen!
> 
With this run, your setting everything that the driver needs to know to 
properly set up the TV. You're forcing the output to the DFP port and 
you're providing both HorizSync/VertRefresh and a modeline for the 
native resolution of the TV. All of this can probably be worked around, 
  providing the driver can properly sense the DFP and CRT ports and get 
the EDID from the the TV thru the DFP port.

> There are some lines about detecting a NTSC tv, could that have something
> to do with the failure to detect the right resolution and output?
> 
NTSC is the default for the TV out port. You can safely ignore this.

> Also, as you can see DRM/DRI isn't working. Xavier thought it wouldn't be
> fixed any time soon, but i'd be happy if Tim could prove him wrong ;)
> 
> Thanks for your effort!
> 
> Auke
> 
Thanks for the tests Auke. I've committed VX800 TMDS patch to svn trunk.

I'm cc'ing openchrome-devel, I shouldn't have sent that privately in the 
first place actually.

Regards,
Xavier