Re: [PATCH 5/9] fujitsu-laptop: fingers off backlight if video.ko

[Thomas Renninger <trenn@suse.de>]

On Thursday 24 July 2008 02:12:47 nokos@gmx.net wrote:
> Hi Jonathan
>
> Am Freitag, den 18.07.2008, 09:37 +0930 schrieb Jonathan Woithe:
> > Hi Peter
> >
> > > Am Mittwoch, den 16.07.2008, 09:25 +0930 schrieb Jonathan Woithe:
> > > > > > It is likely that everything works out with video.ko then.
> > > > > > If not, with a patch I sent recently you should switch off
> > > > > > Windows osi strings with:
> > > > > > acpi_osi=windows_false   (preferred)
> > > > > > or (already works)
> > > > > > acpi_osi="!Windows 2006"
> > > > >
> > > > > disabling windows_osi disables backlight through video.ko and
> > > > > everything works fine with fujitsu_laptop (also brightness-buttons
> > > > > since ACPI then generates events on the fujitsu device) but some
> > > > > other ACPI stuff is disabled too (extended battery status etc...)
> > > >
> > > > As per my previous email, the fact that this works is probably
> > > > because in this instance acpi_video_backlight_support() returns false
> > > > and allows fujitsu-laptop to set up its backlight control functions.
> > >
> > > This behavior seems to be a recent change to the ACPI BIOS
> > > implementation (its in the VIST table, and only takes effect if
> > > osi("Windows 2006") returns true) ... its only my guess thats its hal
> > > who is doing it (with debug="0xffff" on fujitsu_laptop I can verify
> > > that somebody writes to /sys/class/backlight/fujitsu-laptop/brightness
> > > and since it also happens without running windowing environment I
> > > suspect hal). On the S6410 the acpi_osi="!Windows 2006" case probably
> > > resembled the S7020 behavior.
> >
> > Could you please re-test the S6410 with Thomas' latest patch revision?  I
> > tested the S7020 overnight and it seems to work fine with this revision
> > but I suspect the S6410 will still have trouble.  There were some logic
> > fixes in this latest version though so a retest is probably worth it.
>
> I have tested the lastest patch revision and now it works ...
> acpi_video_backlight_support() returns false and only the fujitsu driver
> takes care of manipulating the brightness. Brightness buttons get reported
> by video.ko. I don't exactly know if its only the new patchset since I also
> used a fresh pull of the kernel as basis.
> Interestingly with acpi debug i get
>
> Jul 21 12:16:27 kernel: nsutils-0454 [00] ns_build_internal_name: Returning
> [ffff88012d37a4b0] (rel) "_BCL" Jul 21 12:16:27 kernel: nsaccess-0406 [00]
> ns_lookup             : Searching relative to prefix scope [LCD_]
> (ffff88012fc16000) Jul 21 12:16:27 kernel: nsaccess-0516 [00] ns_lookup    
>         : Simple Pathname (1 segment, Flags=2) Jul 21 12:16:27 kernel:
> nsdump-0087 [00] ns_print_pathname     : [_BCL] Jul 21 12:16:27 kernel:
> nssearch-0109 [00] ns_search_one_scope   : Searching \_SB_.PCI0.GFX0.LCD_
> (ffff88012fc16000) For [_BCL] (Untyped) Jul 21 12:16:27 kernel:
> nssearch-0144 [00] ns_search_one_scope   : Name [_BCL] (Method)
> ffff88012fc4e6c0 found in scope [LCD_] ffff88012fc16000 Jul 21 12:16:27
> kernel: nsutils-0454 [00] ns_build_internal_name: Returning
> [ffff88012d37a4b0] (rel) "_BCM" Jul 21 12:16:27 kernel: nsaccess-0406 [00]
> ns_lookup             : Searching relative to prefix scope [LCD_]
> (ffff88012fc16000) Jul 21 12:16:27 kernel: nsaccess-0516 [00] ns_lookup    
>         : Simple Pathname (1 segment, Flags=2) Jul 21 12:16:27 kernel:
> nsdump-0087 [00] ns_print_pathname     : [_BCM] Jul 21 12:16:27 kernel:
> nssearch-0109 [00] ns_search_one_scope   : Searching \_SB_.PCI0.GFX0.LCD_
> (ffff88012fc16000) For [_BCM] (Untyped) Jul 21 12:16:27 kernel:
> nssearch-0144 [00] ns_search_one_scope   : Name [_BCM] (Method)
> ffff88012fc4e6e0 found in scope [LCD_] ffff88012fc16000
>
> so acpi somehow finds BCL, BCM etc. but nevertheless does video_detect
> report no backlight capability.

That's odd, with the latest patcheset video.ko should be used.
After checking acpidump: Your machine has IGD support and should work with 
Matthew's latest patches (and might break with them if you still load fujitsu 
and video driver without my patches).

Maybe you had not used the very latest version of my patches, there I ripped 
out the IGD check. Can you double check the subject of the initial mail PATCH 
0/X].
Sorry, I only sent the last, 3rd version to Andi and the list:
Check for ACPI backlight support otherwise use vendor ACPI drivers - version 3

But you should really try linux-next or 2.6.27-rcX with only video.ko driver 
loaded and my patchset. This could be the first Fujitsu with IGD 
running/tested on Linux.

Hopefully my patches also find their way upstream, else Matthew's parts 
probably will break with vendor acpi drivers.

        Thomas