Back in April I mentioned the fun and games I had trying to get a nice dual-DVI setup working with my new HP dc7600. The other problem that I’ve been experiencing since then is a complete inability to play any audio.

The machine has an Intel ICH7 High Definition audio chipset onboard which is theoretically supported fine by the snd-hda-intel kernel module, and indeed everything loads fine and shows up in /proc correctly. However nothing ever comes out the speakers! lspci output below


0000:00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 01)
Subsystem: Hewlett-Packard Company: Unknown device 3010
Flags: bus master, fast devsel, latency 0, IRQ 21
Memory at e0a00000 (64-bit, non-prefetchable) [size=16K]
Capabilities:


Today I sat down and tried to work out what was going on, it turns out the Realtek ALC260 chipset that is used on this motherboard supports quite a few different pinouts, so while snd-hda-intel knows how to drive it you don’t actually get any sound unless you have the correct mapping setup! The driver attempts to do this automatically for a number of different motherboards and there is a entry in the table for my particular motherboard (Subsystem 0×3010) mapping it to the ALC260_HP patching, but still nothing works!

Eventually I stumbled across ALSA Bug #2157 which fixes an identical problem for a different motherboard (Subsystem 0×3012) by using the ALC260_HP_3013 mapping in the driver.

So, taking a guess, I made the same change for the 0×3010 mapping, rebooted, and voila, I have sound. Patch below:


--- sound/pci/hda/patch_realtek.c.orig 2006-08-05 21:13:49.000000000 +1200
+++ sound/pci/hda/patch_realtek.c 2006-08-05 20:33:17.000000000 +1200
@@ -2951,7 +2951,7 @@
{ .pci_subvendor = 0x152d, .pci_subdevice = 0x0729,
.config = ALC260_BASIC }, /* CTL Travel Master U553W */
{ .modelname = "hp", .config = ALC260_HP },
- { .pci_subvendor = 0x103c, .pci_subdevice = 0x3010, .config = ALC260_HP },
+ { .pci_subvendor = 0x103c, .pci_subdevice = 0x3010, .config = ALC260_HP_3013 },
{ .pci_subvendor = 0x103c, .pci_subdevice = 0x3011, .config = ALC260_HP },
{ .pci_subvendor = 0x103c, .pci_subdevice = 0x3012, .config = ALC260_HP },
{ .pci_subvendor = 0x103c, .pci_subdevice = 0x3013, .config = ALC260_HP_3013 },