Help. x1600, dual monitors, DVI twitching

Ron King rking at
Tue Sep 1 12:36:46 PDT 2009

Ok, here's the rom code.  Yeah!  I've got strange hardware!  It's a HP 
nx9420 laptop with the advanced docking station.  The dock has one VGA, 
one DVI-D, and one S-Video.  The laptop has one external VGA.

Thanks for the help,

Alex Deucher wrote:
> On Thu, Aug 27, 2009 at 6:25 PM, Ron King<rking at> wrote:
>> Alex Deucher wrote:
>>> On Fri, Aug 7, 2009 at 11:55 AM, Ron King<rking at> wrote:
>>>> Thanks for the try, but that's a no go.  If I use the radeonhd driver and
>>>> attempt to set coherent_mode to false, all monitors blank.  If I set it
>>>> in
>>>> xorg.conf, the X server hangs.  With radeonhd the DVI output is a clone
>>>> of
>>>> LVDS, and both Xrandr and xorg.conf fail when I try to ignore/turn off
>>>> the
>>>> LVDS output.  With the default radeonhd and radeon, I get the flickering
>>>> and
>>>> missing rows.  I pulled the xf86-video-ati, but fails with a
>>>> syntax error on line 12017 with an unknown token XINERAMA.  Unless you,
>>>> or
>>>> someone, has a fairly quick fix, I'm going to drop Fedora 11 and load
>>>> another flavor.  I think Ubuntu is still using the older server and
>>>> drivers.
>>> You need the xorg macros package.  Grab the build deps with yum.
>>> Alex
>> Ok, it seems that Ubuntu has the same problem.  I pulled the latest git and
>> found the same issue.  I tried Alex's coherent_mode change, but it doesn't
>> seem to have any effect at all.  I've attached the Xorg log.
>> My external LCD uses a DVI-D, single link.  Per the specs, VESA 1280 x 1024
>> 63.981 60.020 108.00 +h/+v  When I check the on-screen OSD, it reports that
>> the horizontal rate is 32kHz and the vertical is 30Hz.  These values are
>> half what the manual specs for that mode.  Without delving into the code, I
>> think it would seem that the driver is outputting a DVI-D dual link signal
>> (>165MHz), rather than the expected single link (<165MHz) at 108.0MHz.  If
>> this sounds reasonable, could someone point me to the relevant code so that
>> I might change a few things?
> (II) RADEON(0): Port2:
>   XRANDR name: DVI-0
>   Connector: DVI-I
>   DDC reg: 0x7e50
> Your system uses DVO for the DVI port rather than one of the internal
> TMDS transmitters.  I think this is the first system I've seen like
> that.  I may need to add some additional code to make that work.  Can
> you send me a copy of your video bios?
> To capture the video bios (as root):
> cd /sys/bus/pci/devices/<pci bus id>/
> echo 1 > rom
> cat rom > /tmp/vbios.rom
> echo 0 > rom
> Thanks,
> Alex
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