Bug 32592
| Summary: | Asus UL30VT backlight control only works with acpi_osi="Linux" acpi_osi="!Windows 2009" | ||
|---|---|---|---|
| Product: | ACPI | Reporter: | Alex Williamson (alex.williamson) |
| Component: | Power-Video | Assignee: | Lan Tianyu (tianyu.lan) |
| Status: | CLOSED CODE_FIX | ||
| Severity: | normal | CC: | alan, florian, lenb, rui.zhang, tianyu.lan |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 3.2 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: |
Asus UL30VT Bios 211 DSDT
DSDT.hex debug.patch |
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Created attachment 66492 [details]
DSDT.hex
Please override the DSDT.hex and try again.
(In reply to comment #1) > Created an attachment (id=66492) [details] > DSDT.hex > > Please override the DSDT.hex and try again. No change in behavior with custom DSDT (booting without any acpi_osi options, I get desktop notification from pressing the brightness buttons, but no change in brightness). I see this in my dmesg to confirm the DSDT is being loaded: [ 0.000000] ACPI: Override [DSDT-UL30V200], this is unsafe: tainting kernel The dsdt identifies linux or windows and goes through different code path. So have to set the acpi_osi. Please attach output of the dimcode in order to make a quirk in the kernel. Is this what we want to settle for? Brightness buttons that work, but aren't passed to the OSPM, a constant battle where the desktop app idea of brightness and the platform brightness are rarely in sync? It works under Windows, it works under splashtop (though who knows if they're just passing similar parameters), we should be able to make it work better. Please check whether load the asus-laptop.ko. If not, load and try again without set acpi_osi. If it didn't work, try again with set acpi_blacklight=vendor. It's great that the kernel bugzilla is back. Can you please verify if the problem still exists in the latest upstream kernel? No change on v3.2. Booting with no acpi command line args, the brightness hotkeys are recognized by linux, but do nothing. Manually poking brightness sysfs files also does nothing. does loading asus-laptop driver help? ping... (In reply to comment #8) > does loading asus-laptop driver help? No, it doesn't. asus_laptop reports "Backlight controlled by ACPI video driver" Can you try with param "acpi_blacklight=vendor"? (In reply to comment #11) > Can you try with param "acpi_blacklight=vendor"? Yes, I get backlight control with that. Created attachment 87671 [details]
debug.patch
Ok. Great. Please try this patch.
(In reply to comment #13) > Created an attachment (id=87671) [details] > debug.patch > > Ok. Great. Please try this patch. Seems to work, backlight control with no extra kernel options. Thanks! Welcome. Patch has been sent to ACPI maillist. https://patchwork.kernel.org/patch/1820321/ A patch referencing this bug report has been merged in Linux v3.8-rc1: commit d0c2ce16bec0afa6013b4c5220ca4c9c67210215 Author: Lan Tianyu <tianyu.lan@intel.com> Date: Fri Nov 30 13:02:50 2012 +0100 ACPI / video: Add "Asus UL30VT" to ACPI video detect blacklist |
Created attachment 53362 [details] Asus UL30VT Bios 211 DSDT Asus UL30VT backlight control only works with acpi_osi="Linux" acpi_osi="!Windows 2009". Without these options, I get a desktop notification for the brightness when using the Fn brightness up/down keys, but no change in display brightness. Likewise the sysfs brightness control thinks it's doing it's job when I read and write the file, but there's no change in the display state. Either method causes the display brightness to change when the system is rebooted, as if Linux setup the change, but didn't actually flush it out to hardware.