2.6.25-rc1 regression - IBM ACPI backlight
Hello,
as of 2.6.25-rc1, there is no more /sys/class/backlight/acpi_video1 which controlled LVDS backlight on Lenovo ThinkPad T61. There is still acpi_video0 which seems to have sane values but echo N > brightness has no effect at all.
thinkpad_acpi module reports that ACPI controlled backlight is present.
Signature · 1 line
Lukáš Hejtmánek
Quoted 5 lines · Lukas Hejtmanek
as of 2.6.25-rc1, there is no more
/sys/class/backlight/acpi_video1which controlled LVDS backlight on Lenovo ThinkPad T61. There is stillacpi_video0which seems to have sane values but echo N > brightness has no effect at all.
thinkpad_acpimodule reports that ACPI controlled backlight is present.
Please report this to linux-acpi @ vger . kernel . org...
It is likely caused by the stuff to locate and disable the unused video device in the DSDT (apparently it got the wrong device?!).
However, BEFORE reporting to linux-acpi, please test it in single user mode without X *ever* being loaded on that boot. New X disables the BIOS brightness changes that ACPI uses.
Signature · 4 lines
"One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh
Quoted 7 lines · Henrique de Moraes Holschuh
Quoted 6 lines
as of 2.6.25-rc1, there is no more
/sys/class/backlight/acpi_video1which controlled LVDS backlight on Lenovo ThinkPad T61. There is stillacpi_video0which seems to have sane values but echo N > brightness has no effect at all.
thinkpad_acpimodule reports that ACPI controlled backlight is present.
Quoted 8 lines
Please report this to linux-acpi @ vger . kernel . org...
It is likely caused by the stuff to locate and disable the unused video device in the DSDT (apparently it got the wrong device?!).
However, BEFORE reporting to linux-acpi, please test it in single user mode without X *ever* being loaded on that boot. New X disables the BIOS brightness changes that ACPI uses.
2.6.24 kernel has two acpi_video[01]. 2.6.25-rc1 does not, it contains only acpi_video0 (even in text mode in single user without X being loaded) which does not work at all.
Signature · 5 lines
Lukáš Hejtmánek - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
Quoted 13 lines · Lukas Hejtmanek
Quoted 12 lines · Henrique de Moraes Holschuh
Quoted 6 lines
as of 2.6.25-rc1, there is no more
/sys/class/backlight/acpi_video1which controlled LVDS backlight on Lenovo ThinkPad T61. There is stillacpi_video0which seems to have sane values but echo N > brightness has no effect at all.
thinkpad_acpimodule reports that ACPI controlled backlight is present.Please report this to linux-acpi @ vger . kernel . org...
It is likely caused by the stuff to locate and disable the unused video device in the DSDT (apparently it got the wrong device?!).
Quoted 7 lines
Quoted 3 lines
However, BEFORE reporting to linux-acpi, please test it in single user mode without X *ever* being loaded on that boot. New X disables the BIOS brightness changes that ACPI uses.
2.6.24 kernel has two acpi_video[01]. 2.6.25-rc1 does not, it contains only
acpi_video0(even in text mode in single user without X being loaded) which does not work at all.
The thinkpad DSDT exports two acpi video nodes, but only one is active. Apparently, ACPI video chose the wrong one. You did the test by booting directly to single user mode (without X loading at all since the last reboot), correct? That means there is a bug to report, indeed.
Please report it through http://buzilla.kernel.org, as that's the preferred method of bug reporting by the ACPI people.
Signature · 4 lines
"One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh
Quoted 3 lines · Lukas Hejtmanek
2.6.24 kernel has two acpi_video[01]. 2.6.25-rc1 does not, it contains only
acpi_video0(even in text mode in single user without X being loaded) which does not work at all.
Sigh. Ok. Could you attach the output of acpidump and lspci, please? I'll try to figure out why this is wrong.
Signature · 1 line
Matthew Garrett | [email protected]
Quoted 7 lines · Matthew Garrett
Quoted 3 lines · Lukas Hejtmanek
2.6.24 kernel has two acpi_video[01]. 2.6.25-rc1 does not, it contains only
acpi_video0(even in text mode in single user without X being loaded) which does not work at all.Sigh. Ok. Could you attach the output of acpidump and lspci, please? I'll try to figure out why this is wrong.
I created a bug report here including acpidump and lspci:
http://bugzilla.kernel.org/show_bug.cgi?id=9995
Signature · 5 lines
Lukáš Hejtmánek - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html