| Summary: | backlight control does not works | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Product: | DRI | Reporter: | Sachin Garg <ascii79> | ||||||||||
| Component: | DRM/Intel | Assignee: | ykzhao <yakui.zhao> | ||||||||||
| Status: | CLOSED NOTOURBUG | QA Contact: | Xorg Project Team <xorg-team> | ||||||||||
| Severity: | normal | ||||||||||||
| Priority: | medium | CC: | ascii79, yakui.zhao | ||||||||||
| Version: | unspecified | ||||||||||||
| Hardware: | x86-64 (AMD64) | ||||||||||||
| OS: | Linux (All) | ||||||||||||
| Whiteboard: | |||||||||||||
| i915 platform: | i915 features: | ||||||||||||
| Attachments: |
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Created attachment 32952 [details]
dmesg
Created attachment 32955 [details]
xorg.log
Sounds like an ACPI bug, Yakui please reassign or close as necessary. any updates ? (In reply to comment #4) > any updates ? > Sorry for the late response. Can you confirm whether the backlight can be adjusted by using the following interface? > echo xx >/sys/class/backlight/acpi_video0/brightness Will you please also attach the output of acpidump on your box? The acpidump can be obtained by using pm_tools(20071116), which can be downloaded from: >http://www.lesswatts.org/projects/acpi/utilities.php Thanks. Created attachment 33914 [details]
acpidump of NV59
(In reply to comment #5) > (In reply to comment #4) > > any updates ? > > > Sorry for the late response. > > Can you confirm whether the backlight can be adjusted by using the following > interface? > > echo xx >/sys/class/backlight/acpi_video0/brightness > This does not work. Brightness always stays to maximum > > Will you please also attach the output of acpidump on your box? The acpidump > can be obtained by using pm_tools(20071116), which can be downloaded from: > >http://www.lesswatts.org/projects/acpi/utilities.php > > Thanks. > I have attached the output to the bug Thanks. (In reply to comment #6) > Created an attachment (id=33914) [details] > acpidump of NV59 > thanks for the so quick response. After checking the ACPIdump on this box it seems that the brightness issue is related with the BIOS. The brightness is adjusted by using "_BCM" object, which is defined as the following: > Method (_BCM, 1, NotSerialized) { If (^^^LPCB.EC0.BNCM) { If (^^^LPCB.EC0.ACST) { Store (Local1, ^^^LPCB.EC0.BNAC) } Else { Store (Local1, ^^^LPCB.EC0.BNDC) } } Else { Store (Local1, ^^^LPCB.EC0.BNAC) } } The expected brightness value is written to the internal register of Embedded controller(EC). But unfortunately the brightness can't be adjusted by EC. From me it seems that this is a BIOS bug rather the graphics bug. thanks. Yakui mark as notourbug per last comment from yakui |
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Created attachment 32951 [details] lspci I have new gateway NV59. But I cannot control the backlight of the LCD. It always stays to the maximum. kernel-2.6.33-0.25.rc6.git0.fc13.x86_64 xorg-x11-drv-intel-2.10.0-2.fc13.x86_64 [root@sachin-laptop acpi_video0]# cat /sys/class/backlight/acpi_video0/actual_brightness 0 [root@sachin-laptop acpi_video0]# cat /sys/class/backlight/acpi_video0/brightness 0 [root@sachin-laptop acpi_video0]# cat /sys/class/backlight/acpi_video0/max_brightness 9 [root@sachin-laptop acpi_video0]#