On Tue, May 26, 2015 at 9:47 PM, Darren Hart <dvhart@xxxxxxxxxxxxx> 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? No error, gmux claims it worked: [ 13.693379] apple_gmux: Found gmux version 4.0.8 [indexed] [ 13.693400] vgaarb: device changed decodes: PCI:0000:01:00.0,olddecodes=io+mem,decodes=io+mem:owns=none [ 13.693404] apple_gmux: locked IO for PCI:0000:01:00.0 Full dmesg: https://gist.github.com/marineam/0e5a23548e8b3b2e1d50 -- 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
