Re: [BUG/REGRESSION] DRM / i915 / 2.6.37 and 2.6.38-rc*: DVI outputgets disabled/reenabled under load

From: Knut Petersen
Date: Tue Jan 25 2011 - 09:15:10 EST



>> I think LOG-2.6.38-rc2 shows a sign of an additional bug
>> ===========================================
>> [ 681.527815] [drm:drm_target_preferred], found mode 1280x1024
>> [ 681.531482] [drm:drm_setup_crtcs], picking CRTCs for 4096x4096 config
>>
>> Is 4096x4096 really reasonable? I don't think so, at least not for my
>> hardware.
>>
> Yes, gen3 supports a maximum (square) framebuffer of 4096x4096. X works
> for me with such a virtual screen size (i.e. panning).
>
> The complication comes in that the 3D pipeline is limited to 2048x2048
> coordinates. X tiles, mesa does not and uses software instead. Baring
> bugs, it should work.
>
> If you do have a crash with a recent driver, let me know!
> -Chris
>
>

Well, I don't know if openSuSE 11.3 is recent enough.
Setup: 2 Monitors, attached to VGA1 and DVI1, resolution 1280x1024

xrandr --output VGA1 --pos [1..768]
============================
Everything ok. Works as expected.

xrandr --output VGA1 --pos 769
========================
Xorg Log:

[ 1936.486]
X.Org X Server 1.8.0
Release Date: 2010-04-02
[ 1936.486] X Protocol Version 11, Revision 0
[ 1936.486] Build Operating System: openSUSE SUSE LINUX
[ 1936.486] Current Operating System: Linux golem 2.6.38-rc2-kape #13
PREEMPT Mon Jan 24 18:31:22 CET 2011 i686
[ 1936.486] Kernel command line: root=/dev/sdb5
acpi_enforce_resources=lax drm.debug=0 5
[ 1936.486] Build Date: 19 August 2010 03:34:17PM
[...................]
[ 2199.625]
Backtrace:
[ 2199.625] 0: /usr/bin/Xorg (xorg_backtrace+0x37) [0x80986d7]
[ 2199.626] 1: /usr/bin/Xorg (0x8048000+0x4e3fa) [0x80963fa]
[ 2199.626] 2: (vdso) (__kernel_rt_sigreturn+0x0) [0xb783640c]
[ 2199.626] Segmentation fault at address (nil)
[ 2199.626]
Fatal server error:
[ 2199.626] Caught signal 11 (Segmentation fault). Server aborting

Nothing special in system log, but drm.loglevel was 0.

cu,
Knut
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