[Intel-gfx] Support for HDMI on ASUS P5E-VM HDMI (G35 chipset)

[Hong Liu]

On Mon, 2008-05-26 at 12:37 +0800, Mike Wright wrote:
> Hi all,
> 
> I'm starting to have some luck.  This morning I found out about the
> following xorg.conf option:
> Option "Monitor-TMDS-1" "Monitor0".
> 
> This is needed otherwise all your attempts to program the HDMI output
> end up going to the VGA output :-)
> 
> With this option I was able to get a 1280x720p display over HDMI on my
> plasma.  When X did work, I noticed a 1-2Hz scrolling pair of lines up
> the screen.
> 
> I killed X and started it again and no I get a black screen everytime.
>  I don't think I changed anything.
> 
> I noticed this in the log:
> 
> (II) intel(0): Mode for pipe A:
> (II) intel(0): Modeline "1280x720"x50.0   74.25  1280 1720 1760 1980
> 720 741 746 750 +hsync +vsync (37.5 kHz)
> (II) intel(0): Adjusted mode for pipe A:
> (II) intel(0): Modeline "1280x720"x50.0  148.50  1280 1720 1760 1980
> 720 741 746 750 +hsync +vsync (75.0 kHz)
> chosen: dotclock 148800 vco 1488000 ((m 93, m1 15, m2 6), n 4, (p 10,
> p1 1, p2 10))
> 
> Why is X doubling my pixel clock???
> 
> I think this might be the culprit now.
> 
> Mike.

Actually no :)

This is a requirement of intel SDVO spec. All the sdvo cards can accept
only 100~200MHz clock. Modes with lower pixel clock will be multiplied
with a number to adjust the mode clock to 100~200MHz range, video data
will be duplicated when transferring.

Thanks,
Hong