I've updated kernel on my iBook G4 to latest stable 3.5.7 and now the sound is gone. I'm always trying to keep the same .config file between versions so it must have something changed in the snd driver source. I booted 3.4.9 back and sound is back. Dmesg on 3.4.9 says: [ 9.172879] i2c i2c-0: PMac Keywest Audio: attach_adapter method is deprecated [ 9.179522] i2c i2c-0: Please use another way to instantiate your i2c_client [ 9.186147] i2c i2c-1: PMac Keywest Audio: attach_adapter method is deprecated [ 9.192745] i2c i2c-1: Please use another way to instantiate your i2c_client [ 9.199305] i2c i2c-2: PMac Keywest Audio: attach_adapter method is deprecated [ 9.205880] i2c i2c-2: Please use another way to instantiate your i2c_client [ 9.212573] i2c i2c-3: PMac Keywest Audio: attach_adapter method is deprecated [ 9.219141] i2c i2c-3: Please use another way to instantiate your i2c_client [ 9.225796] i2c i2c-4: PMac Keywest Audio: attach_adapter method is deprecated [ 9.232436] i2c i2c-4: Please use another way to instantiate your i2c_client [ 9.289233] input: PowerMac Beep as /devices/pci0001:10/0001:10:17.0/input/input3 [ 9.297287] i2c i2c-0: aoa_codec_onyx: attach_adapter method is deprecated [ 9.304091] i2c i2c-0: Please use another way to instantiate your i2c_client [ 9.310996] i2c i2c-1: aoa_codec_onyx: attach_adapter method is deprecated [ 9.317913] i2c i2c-1: Please use another way to instantiate your i2c_client [ 9.324838] i2c i2c-2: aoa_codec_onyx: attach_adapter method is deprecated [ 9.331715] i2c i2c-2: Please use another way to instantiate your i2c_client [ 9.338683] i2c i2c-3: aoa_codec_onyx: attach_adapter method is deprecated [ 9.345643] i2c i2c-3: Please use another way to instantiate your i2c_client [ 9.352608] i2c i2c-4: aoa_codec_onyx: attach_adapter method is deprecated [ 9.359587] i2c i2c-4: Please use another way to instantiate your i2c_client [ 9.366681] i2c i2c-0: aoa_codec_tas: attach_adapter method is deprecated [ 9.373721] i2c i2c-0: Please use another way to instantiate your i2c_client [ 9.380767] i2c i2c-1: aoa_codec_tas: attach_adapter method is deprecated [ 9.387806] i2c i2c-1: Please use another way to instantiate your i2c_client [ 9.394826] i2c i2c-2: aoa_codec_tas: attach_adapter method is deprecated [ 9.401819] i2c i2c-2: Please use another way to instantiate your i2c_client [ 9.408818] snd-aoa-codec-tas: found 'deq' node [ 9.408831] i2c i2c-2: Failed to register i2c client aoa_codec_tas at 0x35 (-16) [ 9.415836] i2c i2c-3: aoa_codec_tas: attach_adapter method is deprecated [ 9.422814] i2c i2c-3: Please use another way to instantiate your i2c_client [ 9.429780] i2c i2c-4: aoa_codec_tas: attach_adapter method is deprecated [ 9.436736] i2c i2c-4: Please use another way to instantiate your i2c_client On 3.5.7 it looks pretty much like this above, except that whole aoa_codec_onyx deprecation warnings are gone (!) and tas found message looks different: snd-aoa-codec-tas: tas found, addr ... (I don't have original log now, this is produced by printk(KERN_DEBUG "snd-aoa-codec-tas: tas found, addr 0x%02x on %s\n", addr ... line in /linux/sound/aoa/codecs/snd-aoa-codec-tas.c), theres no "'deq' node" piece in 3.5.7 dmesg. When there's no sound, udev does not create mixer and audio output devices, alsamixer, aumix nor mplayer -ao oss does not work - all these thing complain they can't find devices in /dev tree.
This bug does not affect my other G4 machine (PowerMac alluminium), I upgraded it to 3.5.7 some time ago and sound is working fine, alsamixer starts without single complain, dmesg for 3.5.7 says much less than on iBook: [ 13.835230] snd-powermac no longer handles any machines with a layout-id property in the device-tree, use snd-aoa. [ 13.838870] snd-aoa-fabric-layout: Using direct GPIOs [ 13.839437] snd-aoa-fabric-layout: can use this codec [ 13.908550] snd-aoa-codec-tas: tas found, addr 0x35 on /pci@f2000000/mac-io@17/i2c@18000/deq@6a
s/PowerMac/PowerBook/
See http://lists.lm-sensors.org/pipermail/lm-sensors/2011-April/032320.html which reveals in an short explanation that > attach_adapter is scheduled to be removed in September 2011. The message above is a help call from the ... driver, asking for someone to rewrite it to match the current API. The audio driver and codec have been calling a method that was removed from the kernel over time, the warning produced warns the audio developer of that. So, when the method was finally removed between 3.4.9 and 3.5.7 you no longer have audio since the method is gone. In order to get your audio back, you will need the developer to rewrite the broken part of the audio driver or find an alternative driver if one exists. So, I would suggest you to report this at the kernel bugzilla to at least make the developer(s) aware; make sure to search first, to see if a bug exist already. When you do that, please link this bug to that upstream bug such that the bugs cat track each other. Good luck!
Since the upstream bug is still open, let's see how it proceeds; who knows, some interested developer whom also has the problem might be interested to provide a patch.
A patch from Michael Ellerman was published on kernel bugzilla #52041 that worked for me as I applied it on 3.5.7-gentoo kernel.
