[Openicc] HP Elitebook 8540W notebook with Dreamcolor display

[Emil Briggs]

On Sunday 13 February 2011 07:55:49 Emil Briggs wrote:
> On Sunday 13 February 2011 01:55:52 Kai-Uwe Behrmann wrote:
> > Am 12.02.11, 11:12 -0500 schrieb Emil Briggs:
> > > On Saturday 12 February 2011 10:20:34 Kai-Uwe Behrmann wrote:
> > >> Am 12.02.11, 09:00 -0500 schrieb Emil Briggs:
> > >>> to see what was there and it gave me a "No displays found" message.
> > >>> 
> > >>> i2cdetect -l shows 10 separate /dev/i2c-* nvidia entries so the
> > >>> kernel i2c support is there. I ran hpdc_util again with strace and
> > >>> started looking through the code. The devices are opened
> > >>> successfully but writing to them fails. I'm not quite sure how to
> > >>> proceed next. I do have the Quadro graphics card with the
> > >>> proprietary driver. Just for kicks I tried using the opensource
> > >>> nvidia driver but this does not work -- looking in the Xorg.0.log it
> > >>> finds the I2C/ddc interfaces but is unable to read any EDID
> > >>> information from them.
> > >> 
> > >> Did you see the forum post on the ookala-mcf page around EDID?
> > >> http://sourceforge.net/projects/ookala-mcf/forums/forum/898199/topic/3
> > >> 39 741 5
> > > 
> > > I had not but it's not a permissions issue since I ran it as root after
> > > the it failed as a non privileged user.
> > 
> > Did you try Xcm/libXcm[1] to see the i2c channels?
> > "xcmddc requests EDID from a monitor over the i2c bus."
> > libXcm installs a udev rule for activating the i2c bus.
> 
> No nodes found and strace shows the same thing I saw with hpdc_util.
> 
> 

Made some progress. I unloaded the Nvidia proprietary driver and loaded the 
nouveau kernel module with the framebuffer X driver. The i2c bus appears 
functional now and hpdc_util read the EDID information from the panel. It does 
not recognize it as a Dreamcolor though which is not surprising since it's 
looking for the standalone monitor. If I feel brave I might be able to work 
around this by adding in the ID of the laptop panel. I'm not sure if thats a 
good idea though. Does anyone know if it's possible to damage the hardware 
with an incorrect setting?

For whatever reason the i2c bus is not usable when the Nvidia proprietary 
module is in use. I don't know if that is specific to this card/display 
combination or is more general. Since most people using the proprietary driver 
would be using nvidia-settings to control the displays it might not have been 
noticed.