Bug 41952
Summary: | HP Mini 5103, Backlight only on if charger plugged in at kernel boot time | ||
---|---|---|---|
Product: | ACPI | Reporter: | D Brown (rootytoots) |
Component: | Power-Video | Assignee: | Aaron Lu (aaron.lu) |
Status: | CLOSED INSUFFICIENT_DATA | ||
Severity: | normal | CC: | aaron.lu, rui.zhang |
Priority: | P1 | ||
Hardware: | All | ||
OS: | Linux | ||
Kernel Version: | 3.0 | Subsystem: | |
Regression: | No | Bisected commit-id: | |
Attachments: |
acpidump with backlight off
acpidump with backlight on |
Description
D Brown
2011-08-29 12:12:18 UTC
Created attachment 70772 [details]
acpidump with backlight off
Created attachment 70782 [details]
acpidump with backlight on
I can confirm that if the backlight is on when hibernated (pm-hibernate), the backlight will remain on once resumed. What other information would you like me to provide/test? Cheers (In reply to comment #0) > Hello, > > I have an issue with my HP Mini 5103, where the backlight will only be on if > the adaptor/charger is plugged in before the kernel boots. > Pulling out/plugging in the charger in grub(0.97 legacy) will either turn > off/on the backlight, up until selecting my distribution to boot into (kernel > 3.0-ARCH). > Once I have booted (with the backlight on), I can take out the charger and > the > backlight will remain on. > If I boot without the charger plugged in and then plug in the charger during > running linux, the backlight will still remain off. > With the both the backlight on and off, I have tried changing the values of > bl_power (in /sys/class/backlight/acpi_video0 - symlinked to > /sys/devices/pci0000:00/0000:00:02.0/backlight/acpi_video0) from 0 to 5 (-1 > didn't work), with no change in backlight power (although the change in value > was registered), even rebooting to test the change with no luck. do you mean poking /sys/class/backlight/acpi_video0/actual_brightness can not change the actual backlight? > The value of bl_power with both backlight on and off is 0. > I have tried this both in virtual console and in a basic x setup with no > change > in backlight power. > All other functions of changing the brightness both with Fn Keys and manually > echoing into brightness (max_brightness=24) work fine. what does "manually echoing into brightness" mean? please attach the output of "grep . /sys/class/backlight/*/*" ping... ping... Hi Brown, Are you still there? So your problem is, when you starts the computer without plugging the charger, the screen will be off, and all the way off even after you start Linux, right? The backlight on/off may be controlled by graphics drm driver, but I'm not sure about that. And the fact that before OS starts, the backlight is also off sounds like a BIOS/hardware issue to me. BTW, bl_power isn't implemented for acpi_video sysfs interface, so it won't turn on/off the backlight. |