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). Thanks, Bruno -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
