On Mon, Apr 22, 2013 at 10:07:32PM +0800, Aaron Lu wrote: > On 04/22/2013 09:56 PM, Seth Forshee wrote: > >On Mon, Apr 22, 2013 at 09:40:00PM +0800, Aaron Lu wrote: > >>On 04/22/2013 09:06 PM, Seth Forshee wrote: > >>>On Mon, Apr 22, 2013 at 08:11:17PM +0800, Aaron Lu wrote: > >>>>On 04/22/2013 07:51 PM, Rafael J. Wysocki wrote: > >>>>>I suppose we need to blacklist them to start with. I wouldn't like to apply > >>>>>any general changes before we know how many different systems are affected by > >>>>>this particular issue. > >>>> > >>>>I totally agree. > >>> > >>>Are you sure that all of these machines have an alternate interface for > >>>userspace to change the brightness? I know that I've got a non-Lenovo > >>>machine with nVidia graphics for which nouveau exposes no backlight > >> > >>What's the problem with this system then? The same as the thinkpads in > >>bug 51231? > > > >There's no problem with that system; it has another working backlight > >interface. I'm only mentioning it to demonstrate that taking away the > >ACPI interface could leave some machines without any backlight control > >mechanism that Linux currently supports. > > I think we just need take away the ACPI interface for these known broken > systems for now, that would require: check if we are in win8 mode, if > so, disable acpi video interface for these known broken systems. > > I think video_detect_dmi_table is the proper place to do this. Well, I suppose that's better than what we've got now. I'll post some patches to the bug for testing. Seth -- 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
