On Tue, May 26, 2015 at 10:53 PM, Bruno Prémont <bonbons@xxxxxxxxxxxxxxxxx> wrote: > Hi Michael, > > On Tue, 26 May 2015 21:47:49 -0700 Darren Hart wrote: >> On Tue, May 26, 2015 at 12:10:48PM -0700, Michael Marineau wrote: >> > FYI, this actually broke backlight controls on my MBP11,3 because the >> > assumption the patch makes that gmux is always loaded before graphics >> > drivers didn't hold true. At least for me dracut included the nouveau >> > module in the initrd but not gmux, ensuring the ordering was wrong. No >> > errors were reporting, and gmux still offered the backlight device, it >> > just became inoperable. I worked around this for my kernel by building >> > gmux into vmlinuz instead of as a module but that isn't going to in >> > more general configs because there is an apple backlight driver which >> > cannot be built at all in that configuration. >> >> Thank you for reporting this Michael, >> >> That is tough as nouveau doesn't have an explicit dependency on gmux, so we >> could do something like a passive request_module(), but if it isn't in the >> initrd image, it would still fail as you describe. >> >> > Is there a way to make the ordering between nouveau and gmux more >> > explicit/reliable? Can gmux complain loudly if the ordering is ever >> > wrong? >> >> It should print an error if the probe fails due to the IO already being in use >> or if it can't be allocated. The disabled IO case is only info level though, >> perhaps that should be higher priority. Printing something when failing to probe >> seems like a reasonable thing to do. >> >> Michael, which message do you get if you boot with "debug" or "loglevel=6" when >> apple-gmux is not built-in? > > A full kernel log up to including post-initrd loading of gmux would be > useful. > > As far as I have seen nouveau should not be doing unneeded vgaarb > operations by itself (though userspace might be) as opposed to closed > nvidia driver. > > If your systems allows, try booting to init=/bin/bash, then check for > backlight, load nouveau, check for backlight and finally load gmux and > check backlight (putting i915 in the mix where initrd/userspace puts > it would be nice). Both before and after loading nouveau there is a working acpi_video backlight control. Then after loading gmux it is the only backlight control and it doesn't do anything. -- To unsubscribe from this list: send the line "unsubscribe platform-driver-x86" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
