Re: i915 native backlight never got merged

[Ali Gholami Rudi <aliqrudi@gmail.com>]

Andrew Morton <akpm@linux-foundation.org> wrote:
> 
> On Wed, 10 Aug 2011 07:53:18 -0700 Keith Packard <keithp@keithp.com> wrote:
> > Matthew -- shall I just merge the old patch? Or did you want to make
> > some changes?
> 
> I have a note here that Ali Gholami Rudi <aliqrudi@gmail.com> had issues with
> the version I merged into -mm.

Actually the patch helped me cope with another annoying problem.
The problem is in some kernels the ACPI brightness control
disappears.  Matthew's patches made it possible to access the
native backlight control via sysfs, without which I couldn't
change the brightness of my screen.  So my problem has nothing
to do with Matthew's patches.

Anyhow, the problem is very annoying; it's not just being unable
to change the backlight level, the laptop won't be powered down
and I have to use hold the power to turn it off.  I'm not sure
about other ACPI functions which may be broken as well.  So it
is just possible that it is an ACPI issue.  The kernels I tried
were:

2.6.37		good
2.6.38-rc1	bad
2.6.38+		good
3.0		bad

I may bisect it...

	Ali

$ lspci
00:00.0 Host bridge: Intel Corporation Mobile GME965/GLE960 Memory Controller Hub (rev 0c)
00:02.0 VGA compatible controller: Intel Corporation Mobile GME965/GLE960 Integrated Graphics Controller (rev 0c)
00:02.1 Display controller: Intel Corporation Mobile GME965/GLE960 Integrated Graphics Controller (rev 0c)
00:1a.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #4 (rev 03)
00:1a.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #2 (rev 03)
00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03)
00:1c.0 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 1 (rev 03)
00:1c.5 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 6 (rev 03)
00:1d.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #1 (rev 03)
00:1d.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #2 (rev 03)
00:1d.2 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #3 (rev 03)
00:1d.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #1 (rev 03)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev f3)
00:1f.0 ISA bridge: Intel Corporation 82801HEM (ICH8M) LPC Interface Controller (rev 03)
00:1f.2 SATA controller: Intel Corporation 82801HBM/HEM (ICH8M/ICH8M-E) SATA AHCI Controller (rev 03)
30:00.0 Ethernet controller: Marvell Technology Group Ltd. Device 4357 (rev 10)