Am 29.07.2014 23:35, schrieb Daniel Vetter:
>On Tue, Jul 29, 2014 at 11:09 PM, Jan Niggemann <jn@xxxxxx> wrote:
>>Am 18.07.2014 18:25, schrieb Daniel Vetter:
>>>
>>>On Fri, Jul 18, 2014 at 4:49 PM, Jan Niggemann <jn@xxxxxx> wrote:
>>>
>>>>
>>>>Am 18.07.2014 15:27, schrieb Daniel Vetter:
>>>>>
>>>>>
>>>>>On Thu, Jul 17, 2014 at 10:31:30PM +0200, Jan Niggemann wrote:
>>>>>>
>>>>>>
>>>>>>I'm experiencing an issue with 3.15.5 on my Lenovo T400:
>>>>>>Since 3.15 (or 3.14, can't say for sure), the boot starts
>>>>>>normally, but
>>>>>>the
>>>>>>first mode change doesn't occur, resulting in a black screen
>>>>>>with
>>>>>>backlight
>>>>>>on. The system is entirely unresponsive and I can only press
the
>>>>>>power
>>>>>>button until to switch it off.
>>>>>
>>>>>
>>>>>I think the only way to move forward here is to double-check
that
>>>>>3.14
>>>>>
>>>>>works and 3.15 is broken by recompiling with the same .config
>>>>>(occasionally config changes cause regressions). And then do a
>>>>>full git
>>>>>bisect to find the offending commit.
>>>>
>>>>
>>>>thank you for the feedback.
>>>>I still have all my custom built kernels, I will test 3.14.0
through
>>>>3.14.8
>>>>to make sure those were OK and report back.
>>>
>>>
>>>You only need to test 3.14.0, since the backported fixes only
contain
>>>a very small subset of all patches for 3.15. So it's more
efficient to
>>>then switch to git bisect between 3.14 and 3.15 directly (after
you've
>>>confirmed that 3.15.0 is indeed busted).
>>
>>I familiarized with git bisect, that was something I had never
used
>>before.
>>
>>I started it with "git bisect start v3.15 v3.14 --
drivers/gpu/drm/i915"
>>
>>This lead me to this:
>>
>>cfa7c862982b431add7f2b362526bf31372fc7b0 is the first bad commit
>>commit cfa7c862982b431add7f2b362526bf31372fc7b0
>>Author: Daniel Vetter <daniel.vetter@xxxxxxxx>
>>Date: Tue Apr 29 11:53:58 2014 +0200
>>
>> drm/i915: Sanitize the enable_ppgtt module option once
>>
>> Otherwise we'll end up spamming dmesg on every context
creation on
>>snb
>> with vt-d enabled. This regression was introduced in
>>
>> commit 246cbfb5fb9a1ca0997fbb135464c1ff5bb9c549
>> Author: Ben Widawsky <benjamin.widawsky@xxxxxxxxx>
>> Date: Fri Dec 6 14:11:14 2013 -0800
>>
>> drm/i915: Reorganize intel_enable_ppgtt
>>
>> As the i915.enable_ppgtt is read-only it cannot be changed
after the
>> module is loaded and so we can perform an early sanitization
of the
>> values.
>>
>> v2:
>> - Add comment and pimp commit message (Chris)
>> - Use the param consistently (Jani)
>>
>> v3:
>> - Fix init sequence on pre-gen6 by moving the sanitize_ppgtt
call to
>> gtt_init. Fixes boot hangs on pre-gen6.
>> - Add a debug output for the sanitize ppgtt mode.
>>
>> References: https://lkml.org/lkml/2014/4/17/599
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77916
>> Cc: Alessandro Suardi <alessandro.suardi@xxxxxxxxx>
>> Cc: Ben Widawsky <ben@xxxxxxxxxxxx>
>> Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
>> Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
>> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
>> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
>>
>>:040000 040000 5488e397a1aaa28dca4a252452e9463b0a8f8d10
>>214c8e98b3c72844e48ab7aef02cba7daf139fab M drivers
>>
>>I realized that the issue does always show, contrary to the
subject
>>initially chosen.
>>
>>Unfortunately I can't say anything else, but maybe this will help
you
>>experts spot the issue.
>>If I can help more, be it with testing or anything else, just let
me
>>know.
>
>Hm, I'm not aware of this breaking any gm45 machines, mine here is
>still happy. Can you please make sure that you don't have any i915
>module options set anywhere, either on the kernel cmdline,
modeprobe
>config files in /etc or anywhere else?
My kernel cmdline doesn't have anything, but
/etc/modprobe.d/i915-kms.conf
exists. Its content is this single line: options i915 modeset=1
Can't remember if I created that (it's from 2010) or if it's Debian
default...
grep -Ri i915 /etc/ doesn't show anything else.
grep 915 config-3.15
CONFIG_DRM_I915=m
CONFIG_DRM_I915_KMS=y
CONFIG_DRM_I915_FBDEV=y
# CONFIG_DRM_I915_PRELIMINARY_HW_SUPPORT is not set
# CONFIG_DRM_I915_UMS is not set
CONFIG_SND_HDA_I915=y
Would it help if I included the driver instead of building a module?
