On Tue, 2014-01-21 at 10:24 +0800, Aaron Lu wrote: > On 01/20/2014 09:34 PM, Matthew Garrett wrote: > > On Mon, 2014-01-20 at 16:12 +0800, Aaron Lu wrote: > > > >> 1 remove the win8 OSI check, I've seen win7 laptops that also needs to > >> have only the GPU interface left and checking win8 doesn't make much > >> sense now; > > > > Are we sure that those aren't simply some other bug? > > Well, the firmware on that laptop makes use of EC to do backlight > control and the fact that the firmware interface doesn't work while the > GPU's work seems to indicate that the backlight control circuit is not > routed to EC. I think this is the same case as Win8 laptops. We know that Windows 8 graphics drivers don't use the ACPI interface, and that systems change their behaviour as a result, in some cases with absolutely no way for the ACPI interface could possibly work. I haven't seen any cases where that's obviously true for any non-Windows 8 systems. EC interfaces that don't work are often due to Linux leaving the hardware in a state other than the one expected by the firmware. We shouldn't assume that it's the same issue until we've investigated further. -- Matthew Garrett <matthew.garrett@xxxxxxxxxx> _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
