On Wed, Feb 29, 2012 at 03:23:20PM -0600, Grant Likely wrote: > On Wed, Feb 29, 2012 at 1:50 PM, Seth Forshee > <[email protected]> wrote: > > On Wed, Feb 29, 2012 at 12:43:23PM -0600, Grant Likely wrote: > >> On Wed, Feb 29, 2012 at 11:53 AM, Seth Forshee > >> <[email protected]> wrote: > >> > On Wed, Feb 29, 2012 at 11:46:39AM -0600, Grant Likely wrote: > >> >> On Wed, Feb 22, 2012 at 8:37 AM, Seth Forshee > >> >> <[email protected]> wrote: > >> >> > Apple laptops with hybrid graphics have a device named gmux that > >> >> > controls the muxing of the LVDS panel between the GPUs as well as > >> >> > screen > >> >> > brightness. This driver adds support for the gmux device. Only > >> >> > backlight > >> >> > control is supported initially. > >> >> > > >> >> > Signed-off-by: Seth Forshee <[email protected]> > >> >> > >> >> Works for me. > >> >> > >> >> Tested-by: Grant Likely <[email protected]> > >> >> > >> >> Now I just need to figure out how to get the desktop backlight widget > >> >> to use gmux_backlight instead of acpi_video0... > >> > > >> > The easy way is to pass acpi_backlight=vendor to the kernel, then you > >> > won't have acpi_vidoe0. > >> > >> That did it, thanks. I'm assume something is in the works to set it > >> up automatically? > > > > Not that I'm aware of. A number machines have this problem, that the > > standard ACPI backlight interfaces are implemented but don't work. This > > generally isn't detectable in software; with the Apples at least > > everything looks like it's working except that the brightness doesn't > > change (but not all Apple laptops are affected, so qurking based on > > manufacturer wouldn't work). All we're left with is DMI quirking, which > > isn't practical. Maybe we could add something so a platform driver can > > tell acpi_video that it knows the ACPI backlight doesn't work, but I > > think on some platforms that still is going to be based off of DMI > > information. > > blacklisting based on specific product name (ie. MacBookPro8,*) or > machine model is probably the best. It wouldn't be the first > blacklist in the linux kernel.
I think the blacklist would have to be against specific product names. For example, the MacBook Pro 8,1 has a working acpi_video backlight and no gmux_backlight, the 8,2 has both but only gmux_backlight works, and I suspect the 8,3 is the same as the 8,2. We'd probably end up with an entry in the blacklist for every single model whose acpi_video backlight doesn't work, adding entries for each new generation of MacBooks. And if we start blacklisting Macs we'd have start doing it for other machines too, I guess. From what I've seen, open-ended blacklists like this get nacked pretty consistently nowadays. Seth -- To unsubscribe from this list: send the line "unsubscribe platform-driver-x86" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
