Re: i915: Dell E6410 Ironlake LVDS detection

[Philippe Troin <phil@fifi.org>]

Ben Guthro <ben@guthro.net> writes:

> I have a problematic machine, that I have traced the problem down to
> what I think is an issue with the i915 detection of the LVDS on the
> Ironlake chip.
>
> The machine in question is a Dell Latitude E6410 - i5 quad core
> laptop, with the intel Ironlake chip, and the failure condition is
> such that when the boot sequence switches into KMS mode, the screen
> goes black, and never comes back.

I am seeing similar problems with an HP Elitebook 2540p.

> My base install is Ubuntu 10.04, and I've spun through a few kernels
> to try to bisect the problem. Unfortunately, I've been unable to find
> a kernel that works (including the 2.6.35 RC's, and an ubuntu build of
> drm-intel-next from the beginning of June)

2.6.32 works for me.
2.6.33.5 does not.

I'm currently bisecting the issue, but I do it at a rate of one kernel
a day, so I will need a few more days.

> I can get the machine to come up on an external display, if switched
> at the BIOS screen...but /sys/class/card0 never shows an LVDS
> connector...and dmesg doesn't seem to be throwing any errors.

I'm not sure if this hardware has a LVDS connector.

I was able to boot it with i915 loaded (-> black screen), ssh in and
run xrandr.  Xrandr reported 6 connectors, none of them named LVDS.
It think they were named FP[123].

I was able to turn on an external display connected via VGA with
xrandr and it seemed to be working fine?

Phil.