Black locked screen after inserting only i915 or radeon+starting X with radeon/ati/intel driver
Submitted by tokiclover
Assigned to xf86-video-ati maintainers
Description
Created attachment 48085
dmesg|grep drm
I had this issue since a while, since kernel .36, with different kernel forks.
Depending on the kernel, it was either inserting i915 first or radeon first
that caused the black locked screen. So, identifying the culprit module was
straightforward and the other module was loaded before the culpirit one via
blacklisting. This way, everything was fine and vgaswitcheroo was also
available.
Now a change in my set up going from an unencrypted root to a LUKS encrypted
root--which give me the a chance to make a clean install--screw away that work
around without any clue about what is happening because dmesg is alright when
inserting i915 or radeon for that matter. I even tried going back to an old
stage4 with pf-sources-2.6.38_p6 and gentoo-sources-2.6.38-r2 which worked well
before only to have the same issue. So when inserting radeon or i915 everything
seems alright--but when i915 is loaded before/after or with/without radeon,
whenever i915 is loaded, a black locked screen just come up from nowhere; and
blacklisting i915 and only inserting radeon module, once again dmesg looks
perfectly fine from a module load standpoint, trying to run X with
intel/radeon/ati driver trigger the said locked black screen.
To finish up, when i915 AND radeon are blacklisted and the IGP (GM45) is
active,--and is then the default VGA is the IGP,--the black locked come up
again. When the IGP is disabled and radeon (kernel module) is inserted result
to a completely unusable screen even for the console. fglrx driver doesn't work
for any configuration--IGP on/off--and end up by segment fault to many
libraries and even glibc when everything run perfectly fine--without segement
fault--without fglrx. Where the segment faults come from? I don't know.
So the only usable alternative is IGP disabled and either use VESA driver for
the console,--radeon kernel module is only usable on the console without a
running X server,--either ati/radeon Xorg drivers--without radeon kernel module
then. At least power management features on radeon are quiet good otherwise
with VESA driver my laptop become too hot to be usable.
To conclude, first I thought it was a hardware/BIOS issues with a few suspect
lines in dmeg--ACPI bug--or Xorg.log--failure to read the BIOS--but now I think
it might be a failure to read the BIOS/ROM of the IGP/HD3450M card as seen in
this Bug 18160 because I've even restored the BIOS and nothing, really nothing,
changed.
And I don't really know if it's a kernel issue. However the black locked screen
which came from inserting i915 lead to this way. For the rest, it looks like a
failure to read VGA BIO/ROM when X server is started which is close enough of
the siad bug. However, that bug is old which should/have been fixed. And yes my
set up worked with X server 1.{9.x,8.x,7x} before so I don't know.
Attachment 48085, "dmesg|grep drm":
drm-dmesg