With a powerbook g4 I've had the same problem for the last several kernels and is still a problem with 2.6.24-7-powerpc.
I've discovered that the powerpc-smp image does not have the problem, audio plays fine. I have been using vmlinux-2.6.22-14-powerpc-smp with no audio problems.
Unfortunatly 2.6.24-powerpc-smp is not configured with IDE_PMAC so I can't test it.
With a powerbook g4 I've had the same problem for the last several kernels and is still a problem with 2.6.24-7-powerpc.
I've discovered that the powerpc-smp image does not have the problem, audio plays fine. I have been using vmlinux- 2.6.22- 14-powerpc- smp with no audio problems.
Unfortunatly 2.6.24-powerpc-smp is not configured with IDE_PMAC so I can't test it.
~$ cat /proc/cpuinfo
processor : 0
cpu : 7455, altivec supported
clock : 667.000000MHz
revision : 0.1 (pvr 8001 0201)
bogomips : 66.56
timebase : 33331265
platform : PowerMac
machine : PowerBook3,4
motherboard : PowerBook3,4 MacRISC2 MacRISC Power Macintosh
detected as : 73 (PowerBook Titanium III)
pmac flags : 0000001b
L2 cache : 256K unified
pmac-generation : NewWorld