http://bugzilla.kernel.org/show_bug.cgi?id=9625
------- Comment #6 from [EMAIL PROTECTED] 2008-01-04 07:11 ------- ThinkPad ACPI backlight mode means the firmware doesn't poke the hardware at all when the user presses brightness up/down hot keys. Instead, it just sends the 0x86 and 0x87 notifications to the relevant ACPI display device. You enable it in a thinkpad when you *execute* any _BCL method it provides. ACPI video.c should work fine in a thinkpad... *if* it is working at all, and as long as: 1. video.c is "fixed" to do rounding to the nearest _BCL-provided level instead of setting whatever the user echoed to sysfs (some ThinkPads deal well with it, others apparently don't). 2. We add the capability to tell video.c to NOT export a backlight interface, since it does more (such as video output selection), and *userspace* can be very stupid and do extremely braindamaged things that are not easy at all to debug for, but become apparent if you take away the backlight interfaces it is using to break brightness control :-) 3. We fix the issue video.c has with inactive ACPI nodes that it is exporting interfaces for. As for Xorg and xbacklight, it is sort of a bit of a mess. The very newest versions, I am told, can be configured to: 1. talk to the kernel backlight interface (which one(s) is not properly configurable yet). 2. talk directly to the hardware 3. talk to ACPI(?) or maybe to both. I am not clear on what the third option is. For Lenovo thinkpads, either (1) or (2) is fine if ACPI video is working. Doing both breaks things badly quite fast. Which is why I don't enable thinkpad-acpi's backlight interface on Lenovo thinkpads by default anymore... -- Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ acpi-bugzilla mailing list acpi-bugzilla@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla
