| commit | e11aecf1379e7c4a0293182096e38e5a336696b2 | |
| author | Henrique de Moraes Holschuh <hmh@hmh.eng.br> | |
| Sat, 26 Apr 2008 04:02:21 +0000 (26 01:02 -0300) | ||
| committer | Len Brown <len.brown@intel.com> | |
| Tue, 29 Apr 2008 13:47:01 +0000 (29 09:47 -0400) | ||
| tree | 9dfc915ef98293b7a7b3e42b7a5de9797b0ceb29 | treesnapshot (tar.gz zip) |
| parent | 2d5e94d7ca315f859a0eee1366838e8ad34dd7b2 | commitdiff |
ACPI: thinkpad-acpi: fix brightness dimming control bug
ibm-acpi and thinkpad-acpi did not know about bit 5 of the EC backlight
level control register (EC 0x31), so it was always forced to zero on
any writes.
This would disable the BIOS option to *not* use a dimmer backlight level
scale while on battery, and who knows what else (there are two other
control bits of unknown function).
Bit 5 controls the "reduce backlight levels when on battery" optional
functionality (active low). Bits 6 and 7 are better left alone as well,
instead of being forced to zero.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
ibm-acpi and thinkpad-acpi did not know about bit 5 of the EC backlight
level control register (EC 0x31), so it was always forced to zero on
any writes.
This would disable the BIOS option to *not* use a dimmer backlight level
scale while on battery, and who knows what else (there are two other
control bits of unknown function).
Bit 5 controls the "reduce backlight levels when on battery" optional
functionality (active low). Bits 6 and 7 are better left alone as well,
instead of being forced to zero.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
| drivers/misc/thinkpad_acpi.c | diffblobblamehistory |