[Intel-gfx] Found a bug in i195 driver

[Daniel Vetter]

[Adding some lists to cc]

On Fri, Nov 23, 2012 at 8:12 AM,  <tim.meusel at online-mail.biz> wrote:
> Am 2012-11-22 17:03, schrieb Daniel Vetter:
>
>> On Thu, Nov 22, 2012 at 4:58 PM,  <tim.meusel at online-mail.biz> wrote:
>>>
>>> I think I found a bug in the 1915 driver. I'm not sure if you're the
>>> right
>>> person to talk to, anyway here's the link to my initial ubuntu bug report
>>> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1070690
>>>
>>> As I noticed later, this seems to be a bug in the mainline kernel and not
>>> only the ubuntu versions. It would be awesome if you could help me. Let
>>> me
>>> know if you need further information.
>>
>>
>> Well, you're booting with nomodeset, which then kills the driver
>> because we seem to not properly handle a cleanup cornercase. Please
>> retest on 3.6 and if that's broken, too on the drm-intel-experimental
>> ppa. And please also try booting without nomodeset, things should
>> work.
>> -Daniel
>
>
>
> Hi Daniel,
> I tested several mainline kernel from:
> http://kernel.ubuntu.com/~kernel-ppa/mainline/
> every 3.6.X has this bug with nomodeset:
> [    9.037828] [drm] Initialized drm 1.1.0 20060810
> [    9.163336] [drm:drm_pci_agp_init] *ERROR* Cannot initialize the agpgart
> module.

That's not a bug - nomodeset simply does not work on your chipset -
the only bug is that it OOPS'ed afterwards.


> it seems to work without it:
> root at Ubuntu-1210-quantal-64-minimal ~ # dmesg  | grep drm
> [   10.710566] [drm] Initialized drm 1.1.0 20060810
> [   10.830350] [drm] Supports vblank timestamp caching Rev 1 (10.10.2010).
> [   10.830351] [drm] Driver supports precise vblank timestamp query.
> [   10.897852] [drm] Enabling RC6 states: RC6 on, RC6p on, RC6pp off
> [   11.299615] fbcon: inteldrmfb (fb0) is primary device
> [   11.474424] fb0: inteldrmfb frame buffer device
> [   11.474425] drm: registered panic notifier
> [   11.474964] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on
> minor 0
> root at Ubuntu-1210-quantal-64-minimal ~ # cat /proc/cmdline
> BOOT_IMAGE=/vmlinuz-3.6.6-030606-generic
> root=UUID=a62a7cbf-2e9d-4c42-94da-6b64ddc815f8 ro
> crashkernel=384M-2G:64M,2G-:128M
> root at Ubuntu-1210-quantal-64-minimal ~ #

Nice, I think you should simply boot with kms enabled then ;-)

> Are you talking about
> kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-experimental/ ? the website
> seems to be down, I will test these kernels when it works again.

Yes.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch