Created attachment 36472 [details]
dmesg run with drm.debug=0x04
I posted a similar question to LKML yesterday, but perhaps this is a
better forum for this discussion, as it seemed to get lost amongst
many other non-graphics related discussions.
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
The machine in question is a Dell Latitude E6410 - i5 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.
It seems to be very similar to both
However, I have tried all of the patches suggested on these bugs, to
no avail (yet)
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, but I have settled on linus' 2.6.35rc3 for
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...and
dmesg doesn't seem to be throwing any errors.
Created attachment 36473 [details]
intel_gpu_dump output (compressed)
Created attachment 36474 [details]
output of intel_reg_dumper
Created attachment 36475 [details]
Created attachment 36476 [details]
126.96.36.199 (stock ubuntu 10.04 kernel)
188.8.131.52 (updated ubuntu 10.04 kernel)
2.6.34-rc3 (Unbuntu mainline builds:
2.6.35-rc1 (Ubuntu mainline builds:
2.6.34-drm-intel-next (Intel's DRM branch from ubuntu mainline builds: http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-next/2010-06-02-lucid )
2.6.35-rc3 - vanilla from Linus' git tree
you might want to try the eDP patch I just posted to intel-gfx.
No luck on that eDP patch. The system never completes booting, if booted on the internal display.
does this help any better?
Sadly, no, this still boots to a black screen on 2.6.35-rc3, with this patch applied
I have the same laptop but my machine boots well. Which is your LCD panel? Mine is the simplest model with 1280x800 resolution. Maybe the problem is related to the LCD panel?
Obs: I am also having problem with blank screen, but when resuming from sleep (see bug #28739) or when trying to plug an external monitor (I still need to file a bug on this).
I have the same panel:
[ 9.906428] [drm:drm_mode_debug_printmodeline], Modeline 0:"1280x800" 0 70730 1280 1292 1356 1452 800 803 806 812 0x8 0xa
What kernel are you using?
I am running Ubuntu 10.04 (Lucid) with updated kernel, xorg, and intel drivers from the x-edgers ppa:
The kernel version is:
pjssilva@trinity:/usr/src/linux-2.6.35$ uname -a
Linux trinity 2.6.35-6-generic #8-Ubuntu SMP Mon Jun 28 05:26:19 UTC 2010 x86_64 GNU/Linux
The kernel modesetting works on boot in many other kernels I tried, like the original 2.6.32 from the default Lucid installation.
An interesting point of information...I'm not sure if it is related, or not...
If I boot without an external VGA, I boot successfully, but the screen is black. I can ssh in, and execute any command.
If I boot with an external VGA plugged in (but not active) - the boot never seems to complete - I cannot ssh in.
(In reply to comment #13)
> An interesting point of information...I'm not sure if it is related, or not...
> If I boot without an external VGA, I boot successfully, but the screen is
> black. I can ssh in, and execute any command.
> If I boot with an external VGA plugged in (but not active) - the boot never
> seems to complete - I cannot ssh in.
In my case if I boot without an external VGA everything works fine (but no suspend, however this is another bug).
If I boot with VGA the boot does not complete *unless* I change the output during the BIOS screen (using Fn+F7). If I succeed on switch the output during the BIOS screen, the boot completes correctly but I can not try to revert to the internal LCD back without a reboot (using xrandr). If I try to use xrandr with the two screens attached the system gives me a blank screen and locks. So maybe the problem that you are experiencing may be related to the freezes I get when I try to use xrandr with an external monitor attached.
Created attachment 36580 [details]
dmesg with patch from comment#8
Attached is a boot dmesg with 2.6.35 + patch from comment #8.
It looks like it is probing the eDP, but the screen is still black.
Could I mark this as duplicated of bug #28070 ?
*** This bug has been marked as a duplicate of bug 28070 ***