toshiba_acpi no control of display backlight after suspend to ram
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Invalid
|
Undecided
|
Unassigned |
Bug Description
Hello-
toshiba portege r705
After boot, display backlight control works fine.
After suspend to ram (any number of times), backlight control does not work
After suspend to ram, wake, suspend to disk, wake backlight control returns to working state.
When control is not working, on screen display does work -- indicating backlight changing brightness (even though its not)
/proc/acpi/
/sys/devices/
however--
/sys/devices/
Additionally, the max_brightness=7 and the count starts at 0, but there are only 5 levels when adjusting using control buttons. And even more oddly, when increasing from 0, display_brightness goes like this:
0,2,4,6,7
And when decreasing from 7, it goes like this:
7,5,3,1,0.
Although i think this needs to be filed against a different component, (suggestions?) i thought it might be valid here as well.
tags: | added: kernel-suspend |
tags: | added: kj-triage |
tags: | added: acpi |
tags: | added: acpi-method-return |
tags: | added: acpi-parse-exec-fail |
Changed in linux (Ubuntu): | |
status: | New → Confirmed |
I can confirm this issue also affects the Toshiba R700. If this should be filed upstream can someone recommed where?
It seems the hardware power cycle (shutdown or suspend to disk) is the only way to regain brightness control. The toshest util enables changing the brightness and turning off the backlight before a suspend to ram, but after resuming turning the backlight off and on give odd results dimming and undimming at steps untill the intensity doesn't alter.
http:// ubuntuforums. org/showthread. php?p=9710352