On Thu, Jan 08, 2009 at 02:32:01PM +0800, Zhang Rui wrote: > > Why? These all seem to behave consistently, so I can't see any problem > > with us simply adding support for this varient. > the problem is that the ACPI backlight I/F and the platform I/F coexists > before commit c3d6de698c84efdbdd3781b7058bcc339ab43da8 applied, and the > platform I/F is preferred. For the machines you've looked at - we don't know if that's true for all hardware that behaves this way. > in bug 12249 and 12037, > 1. the first two elements in _BCL are NOT the backlight levels when the > platform is on AC or battery. We can detect that easily and adjust behaviour accordingly. > 2. _BQC returns the index of the current brightness in _BCL package > rather than the value, which surely breaks the ACPI video driver. And again, we can handle that. > 2. every elements in the _BCL package is not a percentage of the maximum > brightness, which is also a violation of ACPI spec. This seems pretty irrelevant - nothing in the code depends on these being percentages. > yes, we can make the ACPI backlight control work by using customized > DSDT. But that's not the fix neither. I don't have any better ideas than > disable them. Just fix up video.c to handle these cases. -- Matthew Garrett | mjg59@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
