[Intel-gfx] KMS broken from 2.6.33 up to 2.6.35-rc5????

[Massimo Maggi]

 Instead of half-solved, I would have written quarter-of-solved!
Setting the brightness higher than 0 works ONLY if the notebook was
powered by battery (and not if it's on AC) when the brightness went to
zero AND when it's reset to a higher number.
To sum up: on battery, the trick works. On AC, it doesn't work.
The notebook has two buttons for lowering and raising brightness:
*On windows: They can set brightness up to the minimal level, but not
zero (turn off screen).
*On linux - powered by battery:  They can set brightness to minimal
level, and turn off screen. The screen always turns on successfully.
*On linux - powered by AC:  They can set brightness to minimal level,
and turn off screen. The screen NEVER turns on. (by buttons, by echo
through ssh, never. Only solution: reboot)
I think that the two behaviours are strictly related.
After loading the i915, on dmesg I see:
[    6.435915] [Firmware Bug]: ACPI: ACPI brightness control misses _BQC
function
and later there are a lot of other ACPI errors (apparently not related
to any problem, actually. Pasted at the end of the mail)
Is possibile that the root of all of my problems with this tablet is a
very buggy BIOS? (improper name, since it's UEFI, based on InsydeH2O)
There's something that can I do other than waiting for the next firmware
version? (mine is up-to-date)
Thanks in advance,
Massimo Maggi
massimo at mmmm.it



[   14.289721] ACPI Error (psargs-0359): [NPSS] Namespace lookup
failure, AE_NOT_FOUND
[   14.289730] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0.PPC_] (Node ffff8801570648e0), AE_NOT_FOUND
[   14.289841] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0._PPC] (Node ffff880157064800), AE_NOT_FOUND
[   14.290699] ACPI Error (psargs-0359): [NPSS] Namespace lookup
failure, AE_NOT_FOUND
[   14.290707] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0.PPC_] (Node ffff8801570648e0), AE_NOT_FOUND
[   14.290817] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0._PPC] (Node ffff880157064800), AE_NOT_FOUND
[   14.290926] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU1._PPC] (Node ffff8801570648c0), AE_NOT_FOUND
[   14.291744] ACPI Error (psargs-0359): [NPSS] Namespace lookup
failure, AE_NOT_FOUND
[   14.291752] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0.PPC_] (Node ffff8801570648e0), AE_NOT_FOUND
[   14.291861] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0._PPC] (Node ffff880157064800), AE_NOT_FOUND
[   14.291969] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU2._PPC] (Node ffff880157064aa0), AE_NOT_FOUND
[   14.293070] ACPI Error (psargs-0359): [NPSS] Namespace lookup
failure, AE_NOT_FOUND
[   14.293078] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0.PPC_] (Node ffff8801570648e0), AE_NOT_FOUND
[   14.293187] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0._PPC] (Node ffff880157064800), AE_NOT_FOUND
[   14.293296] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU3._PPC] (Node ffff880157064a20), AE_NOT_FOUND
[   25.563969] ACPI Error (psargs-0359): [NPSS] Namespace lookup
failure, AE_NOT_FOUND
[   25.563981] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0.PPC_] (Node ffff8801570648e0), AE_NOT_FOUND
[   25.564093] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0._PPC] (Node ffff880157064800), AE_NOT_FOUND
[   25.664344] ACPI Error (psargs-0359): [NPSS] Namespace lookup
failure, AE_NOT_FOUND
[   25.664359] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0.PPC_] (Node ffff8801570648e0), AE_NOT_FOUND
[   25.664504] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0._PPC] (Node ffff880157064800), AE_NOT_FOUND
[   25.664649] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU1._PPC] (Node ffff8801570648c0), AE_NOT_FOUND
[   25.767199] ACPI Error (psargs-0359): [NPSS] Namespace lookup
failure, AE_NOT_FOUND
[   25.767215] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0.PPC_] (Node ffff8801570648e0), AE_NOT_FOUND
[   25.767360] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0._PPC] (Node ffff880157064800), AE_NOT_FOUND
[   25.767501] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU2._PPC] (Node ffff880157064aa0), AE_NOT_FOUND
[   25.867118] ACPI Error (psargs-0359): [NPSS] Namespace lookup
failure, AE_NOT_FOUND
[   25.867132] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0.PPC_] (Node ffff8801570648e0), AE_NOT_FOUND
[   25.867276] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0._PPC] (Node ffff880157064800), AE_NOT_FOUND
[   25.867418] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU3._PPC] (Node ffff880157064a20), AE_NOT_FOUND
[   27.793624] ACPI Error (psargs-0359): [NPSS] Namespace lookup
failure, AE_NOT_FOUND
[   27.793635] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0.PPC_] (Node ffff8801570648e0), AE_NOT_FOUND
[   27.793748] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0._PPC] (Node ffff880157064800), AE_NOT_FOUND
[   27.892629] ACPI Error (psargs-0359): [NPSS] Namespace lookup
failure, AE_NOT_FOUND
[   27.892639] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0.PPC_] (Node ffff8801570648e0), AE_NOT_FOUND
[   27.892770] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0._PPC] (Node ffff880157064800), AE_NOT_FOUND
[   27.892909] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU1._PPC] (Node ffff8801570648c0), AE_NOT_FOUND
[   27.992693] ACPI Error (psargs-0359): [NPSS] Namespace lookup
failure, AE_NOT_FOUND
[   27.992707] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0.PPC_] (Node ffff8801570648e0), AE_NOT_FOUND
[   27.992850] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0._PPC] (Node ffff880157064800), AE_NOT_FOUND
[   27.992990] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU2._PPC] (Node ffff880157064aa0), AE_NOT_FOUND
[   28.092598] ACPI Error (psargs-0359): [NPSS] Namespace lookup
failure, AE_NOT_FOUND
[   28.092611] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0.PPC_] (Node ffff8801570648e0), AE_NOT_FOUND
[   28.092754] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU0._PPC] (Node ffff880157064800), AE_NOT_FOUND
[   28.092894] ACPI Error (psparse-0537): Method parse/execution failed
[\_PR_.CPU3._PPC] (Node ffff880157064a20), AE_NOT_FOUND

Il 18/07/2010 16:42, Massimo Maggi ha scritto:
> After 14 builds (never tought that PXE and Core2Quad were so
> useful!!).... the bad commit is:
>
> 01c66889c14aa163c49355b3be2ccfb214500599 is the first bad commit
> commit 01c66889c14aa163c49355b3be2ccfb214500599
> Author: Zhao Yakui <yakui.zhao at intel.com>
> Date:   Wed Oct 28 05:10:00 2009 +0000
>
>     drm/i915: Add ACPI OpRegion support for Ironlake
>    
>     Add the support of ACPI opregion on Ironlake so that the backlight
>     brightness can be adjusted by using ACPI interface
>        >/sys/class/backlight/acpi_video0/brightness
>    
>     Signed-off-by: Zhao Yakui <yakui.zhao at intel.com>
>     Tested-by: Zhao Yakui <yakui.zhao at intel.com>
>     [zhenyuw: cleanups, fix typo for checking GSE irq and convert to
>     current irq handling logic.]
>     Signed-off-by: Zhenyu Wang <zhenyuw at linux.intel.com>
>     Signed-off-by: Eric Anholt <eric at anholt.net>
>
> :040000 040000 79f96cd37f779fb2b33f0e6545e83f32cd5c1372
> 3b9f77adfeed13386058a46a17e3f4facd8d862c M      drivers
>
> The problem is *half*-solved...
> connecting by ssh (as root) and typing
> # echo -n 10 >/sys/class/backlight/acpi_video0/brightness
> revives the screen.
> Starting X gives me a fully working KWin compositing (with OpenGL)
> I will temporarily put this line in an init script, but I think that
> this bug must be solved as soon as possible!
> Another question:
> How can I be sure that the ATI gpu isn't wasting power while PC is
> booted in Linux?
> Best regards,
> Massimo Maggi
> massimo at mmmm.it
>
>
> Il 18/07/2010 14:57, Chris Wilson ha scritto:
>> On Sun, 18 Jul 2010 14:29:34 +0200, Massimo Maggi <massimo at mmmm.it> wrote:
>>> I've set up a very minimal kernel config (the resulting kernel is not
>>> useful for anything except showing the problem), and built versions:
>>> 2.6.32.16
>>> 2.6.33.6
>>> 2.6.34.1
>>> 2.6.35-rc5
>>> Only 2.6.32.16 is able to correctly initialize the framebuffer.
>> Excellent, as you have managed to reproduce this with a minimal kernel,
>> can you do a bisect between 2.6.33.16 and 2.6.33.6 and see which patch
>> causes the regression? It should only take a couple of hours. My bet is
>> one of the Arrandale enabling patches...
>>
>