On Mon, 31 Dec 2007, Ben Liblit wrote: > Henrique de Moraes Holschuh wrote: > > No bugs, then. It is a Lenovo BIOS issue. Which doesn't mean we > > can't do anything about it (besides asking Lenovo for a fix), but I > > am not sure of what. > > There must surely be *something* we can do about it, given that the > brightness controls work perfectly under Vista. That proves it's at > least possible to make this work on the current hardware, with the > current BIOS. Oh, it will work alright. We just need to place the ThinkPad in ACPI brightness mode (as simple as calling _BCL), trap in userspace the generic ACPI brightness change events, and use xbacklight to change the backlight level. We just need to get video.c to cooperate, the thinkpad-acpi side is trivial and I will address it soon. > That same offer still stands regarding the fact that when using the > video module, /sys/class/backlight/acpi_video1 treats levels 0-19 as > no-ops. I am happy to open technical support request with > Lenovo complaining about this as a BIOS bug, but I need you to write (or > help me write) that text. You said that this is a Lenovo BIOS bug, I > really don't know the first thing about ACPI internals, so I wouldn't > even know how to describe the problem. I'd need to re-read the ACPI spec to know if we can really complain about it. But as I said, someone already promissed to address this issue in the Linux video.c driver anyway, and what he proposes would work around any such BIOS limitations. > > BTW, if I was sure it was a better idea to use the ACPI video > > interface before, I am more even so now. > > Does that mean I de-blacklist the video module and go back to trying to > get that debugged to the point of usability? Or are you saying that the Since you already provided me with the push, and information, needed to get everything fixed in the thinkpad-acpi side, I'd say that helping the ACPI video.c driver now is probably the best idea, yes. But you don't have to wait for fixes anywhere to use your backlight. Here's what you can do: 1. load latest thinkpad-acpi in whichever way you want (with or without backlight interface). It will work well enough, AFAIK. 2. load and then *UNLOAD* the ACPI video module. This will place the thinkpad in ACPI backlight mode. 3. have userspace use one (and just one!) method of changing backlight levels (xbacklight, thinkpad-acpi) when the ACPI backlight level request change events happen. You will see those events using acpi_listen and pressing the brightness up/down hot keys. This is actually the hard part, as acpid, X.org and HAL could each be trying to respond to these events and thus causing a mess. -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh ------------------------------------------------------------------------- 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/ _______________________________________________ ibm-acpi-devel mailing list ibm-acpi-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/ibm-acpi-devel
