Bug 15764
| Summary: | Samsung P460 screen brightness control does not work | ||
|---|---|---|---|
| Product: | ACPI | Reporter: | Claas Langbehn (claas) |
| Component: | Power-Video | Assignee: | Zhang Rui (rui.zhang) |
| Status: | REJECTED UNREPRODUCIBLE | ||
| Severity: | normal | CC: | rui.zhang |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 2.6.32-19 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: |
dmesg
dmesg when booting with acpi_osi=Linux acpi DSDT lspci lspci -vn lspci -vvv dmidecode biosdecode |
||
Created attachment 25949 [details]
dmesg when booting with acpi_osi=Linux
Created attachment 25950 [details]
acpi DSDT
Created attachment 25951 [details]
lspci
Created attachment 25952 [details]
lspci -vn
Created attachment 25953 [details]
lspci -vvv
Created attachment 25954 [details]
dmidecode
Created attachment 25955 [details]
biosdecode
I forgot to mention that the hotkeys for brightness control Fn+cursor_up (increase brightness) and FN+cursor_down (decrease brightness) also don't function. The key scancodes are reported to syslog: # Brightness up kernel: [ 2495.235118] atkbd.c: Unknown key pressed (translated set 2, code 0x88 on isa0060/serio0). kernel: [ 2495.235127] atkbd.c: Use 'setkeycodes e008 <keycode>' to make it known. # Brightness down kernel: [ 2496.991297] atkbd.c: Unknown key pressed (translated set 2, code 0x89 on isa0060/serio0). kernel: [ 2496.991306] atkbd.c: Use 'setkeycodes e009 <keycode>' to make it known. $ acpi -c Cooling 0: LCD 0 of 7 Cooling 1: Processor 0 of 10 Cooling 2: Processor 0 of 10 Cooling 3: Fan 0 of 1 Cooling 4: Fan 0 of 1 What's cooling 0 about? The notebook also has an ambient light sensor. I did not find a way to read the values. Any hints? Under windows this is used to auto-adjust the screen brightness according to the ambient light. Method (_BCM, 1, NotSerialized)
{
If (LGreaterEqual (OSYS, 0x07D6))
{
Store (Arg0, BRTL)
SECS (0xA6)
}
}
Method (SECS, 1, Serialized)
{
Acquire (MSEC, 0xFFFF)
Store (Arg0, SECI)
Store (Zero, TRPS)
Release (MSEC)
}
As the BIOS changes the backlight in SMM, I don't think there is anything we can do if it doesn't work.
(In reply to comment #8)
> The notebook also has an ambient light sensor. I did not find a way to read
> the
> values. Any hints? Under windows this is used to auto-adjust the screen
> brightness according to the ambient light.
This is a hint.
I have a HP laptop with ambient light sensor. And I can not change the backlight manually in Windows, unless I disable the ambient light sensor.
So can you please disable it and try again? (BTW, there is a hotkey to enable/disable the ALS on my laptop)
ping... There is a windows utility to activate the ambient light sensor, it was disabled by default. I did not try to enable it because I did not expect it to work with linux. I wrote an email to the support@samsung, and they replied that they could not help me as they only support Windows. They know about this linux issue, but they don't want to help. Sorry Samsung, but that's not acceptable. I'll buy a Lenovo or HP now. Since I returned the notebook to the dealer, I can not do further tests. What shall we do with the status of this bug? Close it as it seems to be a bug of the notbook's BIOS? okay, close this bug report as we can not reproduce it for now. we can re-open it if the bug can be reproduced by anybody else. |
Created attachment 25948 [details] dmesg System: Samsung P460 notebook, BIOS-version 07LQ (current version) Core 2 Duo P7350 2x 2.00GHz, Intel GMA X4500HD IGP $ cat /proc/acpi/video/GFX0/DD04/brightness levels: 25 35 45 60 70 80 90 100 current: 100 $ echo -n 25 > /proc/acpi/video/GFX0/DD04/brightness has no effect on the brightness It seems to me that this is caused by the system BIOS: $ dmesg | grep brightness [ 0.208482] [Firmware Bug]: ACPI: ACPI brightness control misses _BQC function I also tried booting with acpi_osi=Linux but with no changes.