Archive:Intel Linux Modifications for HD Audio

Kernel

HD Audio on Intel SandyBridge & IvyBridge systems require a patch from Intel to be included within the kernel, Linux 3.7 and higher include this patch as standard.

For more on this patch refer to Intel HDMI HBR patches for HD Audio

Intel Systems with both SPDIF & HDMI

On system which have a Intel GPU feeding a HDMI out but also have a motherboard SPDIF out then getting sound on the HDMI out will not be possible without system file modifications. In these circumstances both SPDIF & HDMI share certain system file settings which cause a conflict resulting in the HDMI sound being blocked, to fix this there are two options available:

1. Easy - Blacklist the SPDIF so only HDMI is available for audio, this also has the advantage of surviving system upgrades.
2. Difficult - Editing the HDA-Intel.conf so there is no conflict in the device settings.

Difficult - HDA-Intel.conf - Fix

WARNING: Only carry this out if you 100% know what you are doing as a wrong step can totally break audio.

This fix requires modification to:

/usr/share/alsa/cards/HDA-Intel.conf

Open the HDA-Intel.conf file with a editor and look for entries containing:

"CTLINDEX="

The numerical value after the = sign need to be increased by 1 so for example "CTLINDEX=1" becomes "CTLINDEX=2"

Example of original /usr/share/alsa/cards/HDA-Intel.conf file

@@ -211,7 +211,7 @@ HDA-Intel.pcm.hdmi.0 {
"cards.HDA-Intel.pcm.hdmi.common:"
"CARD=" $CARD ","
"DEVICE=3,"
"CTLINDEX=0,"

"AES0=" $AES0 ","
"AES1=" $AES1 ","
"AES2=" $AES2 ","
@@ -234,7 +234,7 @@ HDA-Intel.pcm.hdmi.1 {
"cards.HDA-Intel.pcm.hdmi.common:"
"CARD=" $CARD ","
"DEVICE=7,"
"CTLINDEX=1,"

"AES0=" $AES0 ","
"AES1=" $AES1 ","
"AES2=" $AES2 ","
@@ -257,7 +257,7 @@ HDA-Intel.pcm.hdmi.2 {
"cards.HDA-Intel.pcm.hdmi.common:"
"CARD=" $CARD ","
"DEVICE=8,"
"CTLINDEX=2,"
"AES0=" $AES0 ","
"AES1=" $AES1 ","
"AES2=" $AES2 ","
@@ -280,7 +280,7 @@ HDA-Intel.pcm.hdmi.3 {
"cards.HDA-Intel.pcm.hdmi.common:"
"CARD=" $CARD ","
"DEVICE=9,"
"CTLINDEX=3,"
"AES0=" $AES0 ","
"AES1=" $AES1 ","
"AES2=" $AES2 ","

Becomes

@@ -211,7 +211,7 @@ HDA-Intel.pcm.hdmi.0 {
"cards.HDA-Intel.pcm.hdmi.common:"
"CARD=" $CARD ","
"DEVICE=3,"
"CTLINDEX=1,"
"AES0=" $AES0 ","
"AES1=" $AES1 ","
"AES2=" $AES2 ","
@@ -234,7 +234,7 @@ HDA-Intel.pcm.hdmi.1 {
"cards.HDA-Intel.pcm.hdmi.common:"
"CARD=" $CARD ","
"DEVICE=7,"
"CTLINDEX=2,"
"AES0=" $AES0 ","
"AES1=" $AES1 ","
"AES2=" $AES2 ","
@@ -257,7 +257,7 @@ HDA-Intel.pcm.hdmi.2 {
"cards.HDA-Intel.pcm.hdmi.common:"
"CARD=" $CARD ","
"DEVICE=8,"
"CTLINDEX=3,"
"AES0=" $AES0 ","
"AES1=" $AES1 ","
"AES2=" $AES2 ","
@@ -280,7 +280,7 @@ HDA-Intel.pcm.hdmi.3 {
"cards.HDA-Intel.pcm.hdmi.common:"
"CARD=" $CARD ","
"DEVICE=9,"
"CTLINDEX=4,"
"AES0=" $AES0 ","
"AES1=" $AES1 ","
"AES2=" $AES2 ","