Public bug reported:
Ubuntu does not always turn on the backlight properly for the HP
Touchsmart tm2 laptop. I have debugged this issue and it seems to be
related to the _BCL ACPI function.
The original code is:
Method (OBCL, 0, NotSerialized)
{
BINI ()
If (LEqual (IOSR, One))
{
Return (Package (0x0D)
{
0x64,
0x3C,
0x06,
0x0A,
0x14,
0x1E,
0x28,
0x32,
0x3C,
0x46,
0x50,
0x5A,
0x64
})
}
Else
{
Store (Package (0x0D)
{
0x64,
0x3C,
Zero,
0x0A,
0x14,
0x1E,
0x28,
0x32,
0x3C,
0x46,
0x50,
0x5A,
0x64
}, Local0)
If (LEqual (OSYS, 0x07D6))
{
Return (Package (0x0D)
{
0x64,
0x3C,
0x06,
0x0A,
0x14,
0x1E,
0x28,
0x32,
0x3C,
0x46,
0x50,
0x5A,
0x64
})
}
Return (Local0)
}
}
In this original code, if IOSR isn't 1 and the OS is not Vista, the backlight
table will contain 0 for the third entry instead of 6. If Linux sets the
backlight to 0, it doesn't seem to be able to turn it on again. I don't know
what conditions will cause IOSR to change. Hacking the code to the following
seems to fix it and does not affect Windows 7, but I feel that hacking the BIOS
is not the best solution and the best long term solution is to make Linux work
around the issue:
Method (OBCL, 0, NotSerialized)
{
BINI ()
Return (Package (0x0D)
{
0x64,
0x3C,
0x06,
0x0A,
0x14,
0x1E,
0x28,
0x32,
0x3C,
0x46,
0x50,
0x5A,
0x64
})
}
An unrelated issue is that there is only one _BQC function for the two
graphics cards (Intel, ATI), which confuses Linux and makes it unable to
correctly determine the current backlight level, which confuses the
GNOME backlight widget. I haven't been able to fix this one.
ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: linux-image-2.6.35-24-generic 2.6.35-24.42
Regression: No
Reproducible: Yes
ProcVersionSignature: Ubuntu 2.6.35-24.42-generic 2.6.35.8
Uname: Linux 2.6.35-24-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
AplayDevices: aplay: device_list:235: no soundcards found...
Architecture: amd64
ArecordDevices: arecord: device_list:235: no soundcards found...
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/controlC0',
'/dev/snd/hwC0D0', '/dev/snd/pcmC0D0c', '/dev/snd/pcmC0D0p', '/dev/snd/seq',
'/dev/snd/timer'] failed with exit code 1:
CRDA: Error: [Errno 2] No such file or directory
Date: Tue Jan 4 21:10:33 2011
HibernationDevice: RESUME=UUID=0e1f69a5-b0a9-489b-97d9-f7ab6df34bfb
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
MachineType: Hewlett-Packard HP TouchSmart tm2 Notebook PC
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.35-24-generic
root=UUID=3a3bdef2-d2b1-42e9-b4f4-8774f733d24a ro quiet splash
ProcEnviron:
PATH=(custom, user)
LANG=en_US.utf8
SHELL=/bin/bash
RelatedPackageVersions: linux-firmware 1.38
SourcePackage: linux
dmi.bios.date: 07/30/2010
dmi.bios.vendor: Insyde
dmi.bios.version: F.12
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: 1486
dmi.board.vendor: Hewlett-Packard
dmi.board.version: 83.1A
dmi.chassis.asset.tag: CNU03037KH
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.chassis.version: Chassis Version
dmi.modalias:
dmi:bvnInsyde:bvrF.12:bd07/30/2010:svnHewlett-Packard:pnHPTouchSmarttm2NotebookPC:pvr0489200000252A20001220000:rvnHewlett-Packard:rn1486:rvr83.1A:cvnHewlett-Packard:ct10:cvrChassisVersion:
dmi.product.name: HP TouchSmart tm2 Notebook PC
dmi.product.version: 0489200000252A20001220000
dmi.sys.vendor: Hewlett-Packard
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug kernel-graphics maverick needs-upstream-testing
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https://bugs.launchpad.net/bugs/697514
Title:
Problem with HP Touchsmart tm2 backlight
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