Using alsa-driver-1.0.14rc3 with an iMac Core2 Duo 24" results in audio only available through the headphones. Additionally the sound is very low, even at the highest mixer setting.
This problem is very similar to the bug recently fixed in 1.0.14rc2 with the audio on the MacPro. I was able to make a patch that applies the same fix for the MacPro to my iMac. The patch fixes the audio so that the built in speakers work normally, but now the headphones do not work at all. Obviously some more work is needed on this.
The patch I've attached just adds my device's' PCI SSID to an existing switch statement.
I am willing to provide some more testing if necessary.
Here is my systems info:
00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 02) Subsystem: Realtek Semiconductor Co., Ltd. Unknown device 0885 Flags: bus master, fast devsel, latency 0, IRQ 21 Memory at 92400000 (64-bit, non-prefetchable) [size=16K] Capabilities: [50] Power Management version 2 Capabilities: [60] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable- Capabilities: [70] Express Unknown type IRQ 0
# cat /proc/asound/card0/codec#0 Codec: Realtek ALC885 Address: 0 Vendor Id: 0x10ec0885 Subsystem Id: 0x106b1000 Revision Id: 0x100103
# cat /proc/asound/version Advanced Linux Sound Architecture Driver Version 1.0.14rc3. Compiled on Apr 22 2007 for kernel 2.6.20-15-generic (SMP).