Second monitor on dual-head I915 video not initialized sometimes

[Alex Deucher]

On 8/8/07, Kalin Nakov <kalin.nakov at gmail.com> wrote:
> Hello,
>
> Our problem concerns the i810 driver.  Sometimes, once in 40-50 hard
> restarts of the computer the second monitor does not start. Our system has a
> dual-head I915 video embedded in the north bridge. The two independent
> outputs of the video go into two monitors. The X config file is configured
> with two monitors. In the rare cases when the second monitor does not start,
> we have measured the output of the second video card inside the north bridge
> with oscilloscope and found out that there is absolutely no signal going out
> of the north bridge. I still don't know if the problem is in the hardware or
> in the software, but I believe there is some code in the i810 driver that
> disables or enables the video output depending on the circumstances. Maybe
> because of some racing condition sometimes the second video card gets
> disabled.

What version of the driver are you using?  if you are still using the
old bios-based i810 driver, you should try the newer intel driver with
native mode setting.

Alex