i915.invert_brightness=1

[Daniel Vetter]

On Sun, Oct 20, 2013 at 10:43:57PM +0200, Grethus Bode wrote:
> Hello dri developer,
> 
> I have a laptop (Acer Aspire 5336) which needs the i915.invert_brightness=1 option set to get the brightness correct.
> 
> running Linux 3.7.10-1.16-desktop, openSUSE 12.3 (Dartmouth) (i586)
> 
> Via modinfo i915 I found this mail address and a note to send some info if my machine needed this option.
> 
> Via hwinfo --gfxcard I got this info, I hope it is enough:
> 09: PCI 02.0: 0300 VGA compatible controller (VGA)              
>   [Created at pci.319]
>   Unique ID: _Znp.LBJf8FUrAvC
>   SysFS ID: /devices/pci0000:00/0000:00:02.0
>   SysFS BusID: 0000:00:02.0
>   Hardware Class: graphics card
>   Model: "Intel Mobile 4 Series Chipset Integrated Graphics Controller"
>   Vendor: pci 0x8086 "Intel Corporation"
>   Device: pci 0x2a42 "Mobile 4 Series Chipset Integrated Graphics Controller"
>   SubVendor: pci 0x1025 "Acer Incorporated [ALI]"
>   SubDevice: pci 0x048a 
>   Revision: 0x09
>   Driver: "i915"
>   Driver Modules: "drm"
>   Memory Range: 0x90000000-0x903fffff (rw,non-prefetchable)
>   Memory Range: 0x80000000-0x8fffffff (ro,non-prefetchable)
>   I/O Ports: 0x4110-0x4117 (rw)
>   IRQ: 44 (57336 events)
>   I/O Ports: 0x3c0-0x3df (rw)
>   Module Alias: "pci:v00008086d00002A42sv00001025sd0000048Abc03sc00i00"
>   Driver Info #0:
>     Driver Status: i915 is active
>     Driver Activation Cmd: "modprobe i915"
>   Config Status: cfg=no, avail=yes, need=no, active=unknown
> 
> 10: PCI 02.1: 0380 Display controller
>   [Created at pci.319]
>   Unique ID: ruGf.sdgH25nVSW2
>   SysFS ID: /devices/pci0000:00/0000:00:02.1
>   SysFS BusID: 0000:00:02.1
>   Hardware Class: graphics card
>   Model: "Intel Mobile 4 Series Chipset Integrated Graphics Controller"
>   Vendor: pci 0x8086 "Intel Corporation"
>   Device: pci 0x2a43 "Mobile 4 Series Chipset Integrated Graphics Controller"
>   SubVendor: pci 0x1025 "Acer Incorporated [ALI]"
>   SubDevice: pci 0x048a 
>   Revision: 0x09
>   Memory Range: 0x93400000-0x934fffff (rw,non-prefetchable)
>   Module Alias: "pci:v00008086d00002A43sv00001025sd0000048Abc03sc80i00"
>   Config Status: cfg=no, avail=yes, need=no, active=unknown
> 
> Primary display adapter: #9
> 
> With Regards

We've applied a catch-all w/a patch for all Acer gm45 machines. It'll land
in 3.13 and if it doesn't blow up anywhere we can backport it to stable
kernels. Commit in linux-next is

commit ee1452d7458451a7508e0663553ce88d63958157
Author: Jani Nikula <jani.nikula at intel.com>
Date:   Fri Sep 20 15:05:30 2013 +0300

    drm/i915: assume all GM45 Acer laptops use inverted backlight PWM

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