[Bug 630888] [NEW] ACPI issues / brightness on ASUS Laptop (K50IJ) -- Fix Available

[Paolo Ornati]

Public bug reported:

Binary package hint: linux-image-2.6.32-24-generic

On this laptop (ASUS K50IJ), with 2.6.32 based kernels I get these ACPI
errors in dmesg:

[   19.590966] ACPI Exception: AE_AML_BUFFER_LIMIT, Index (000000064) is beyond end of object (20090903/exoparg2-445)
[   19.590975] ACPI Error (psparse-0537): Method parse/execution failed [\_SB_.PCI0.SBRG.EC0_.STBR] (Node ffff88013ba43180), AE_AML_BUFFER_LIMIT
[   19.591015] ACPI Error (psparse-0537): Method parse/execution failed [\_SB_.PCI0.VGA_.LCDD._BCM] (Node ffff88013ba3d400), AE_AML_BUFFER_LIMIT
[   19.591057] ACPI Error: Evaluating _BCM failed (20090903/video-528)

Changing brightness doesn't work.

This was fixed in vanilla kernel between 2.6.32 and 2.6.33 by this
commit:

-------------------------------------------------------------------------------------------
commit 81074e90f5c150ca70ab8dfcc77860cbe76f364d
Author: Zhang Rui <rui.zhang at intel.com>
Date:   Mon Dec 21 16:13:15 2009 +0800

    ACPI: disable _OSI(Windows 2009) on Asus K50IJ
    
    Fix a win7 compability issue on Asus K50IJ.
    
    Here is the _BCM method of this laptop:
                        Method (_BCM, 1, NotSerialized)
                        {
                            If (LGreaterEqual (OSFG, OSVT))
                            {
                                If (LNotEqual (OSFG, OSW7))
                                {
                                    Store (One, BCMD)
                                    Store (GCBL (Arg0), Local0)
                                    Subtract (0x0F, Local0, LBTN)
                                    ^^^SBRG.EC0.STBR ()
                                    ...
                                }
                                Else
                                {
                                    DBGR (0x0B, Zero, Zero, Arg0)
                                    Store (Arg0, LBTN)
                                    ^^^SBRG.EC0.STBR ()
                                    ...
                                }
                            }
                        }
    LBTN is used to store the index of the brightness level in the _BCL.
    GCBL is a method that convert the percentage value to the index value.
    If _OSI(Windows 2009) is not disabled, LBTN is stored a percentage
    value which is surely beyond the end of _BCL package.
    
    http://bugzilla.kernel.org/show_bug.cgi?id=14753
------------------------------------------------------------------------------------

Please add this workaround to Ubuntu Lucid kernel.

Debian Squeeze kernel needs this too.

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New

** Affects: linux-latest-2.6 (Debian)
     Importance: Undecided
         Status: New

-- 
ACPI issues / brightness on ASUS Laptop (K50IJ) -- Fix Available
https://bugs.launchpad.net/bugs/630888
You received this bug notification because you are a member of Kernel
Bugs, which is subscribed to linux in ubuntu.