On Fri, 18 Apr 2014, Thomas Petazzoni wrote:

Simple mixer control 'Analog',0 Capabilities: pvolume Playback channels: Front Left - Front Right Limits: Playback 0 - 177

This is wrong

Mono: Front Left: Playback 204 [115%] [0.00dB] Front Right: Playback 204 [115%] [0.00dB]

root@beagleboard:~# amixer sget 'Analog' Simple mixer control 'Analog',0 Capabilities: pvolume penum Playback channels: Front Left - Front Right Limits: Playback 0 - 229 Mono: Front Left: Playback 204 [89%] [0.00dB] Front Right: Playback 204 [89%] [0.00dB]

root@beagleboard:~# i2cdump -y -f 1 0x4b No size specified (using byte-data access) 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef 00: 00 d9 7e ae 00 00 a0 00 60 44 00 00 00 00 84 84 .?~?..?.`D....?? 10: 19 19 00 00 00 88 00 00 00 00 7f 00 01 3f 00 00 ??...?....?.??.. [...]

As you can see the output of amixer is wrong on your system. There are 229 steps for gain on this control. At 89% we are at 0dB which is correct according to I2C Tools (0h)

root@beagleboard:~# amixer sset 'Analog' 0 Simple mixer control 'Analog',0 Capabilities: pvolume penum Playback channels: Front Left - Front Right Limits: Playback 0 - 229 Mono: Front Left: Playback 0 [0%] [-102.00dB] Front Right: Playback 0 [0%] [-102.00dB] root@beagleboard:~# i2cdump -y -f 1 0x4b No size specified (using byte-data access) 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef 00: 00 d9 7e ae 00 00 a0 00 60 44 00 00 00 00 84 84 .?~?..?.`D....?? 10: 19 19 00 00 00 88 34 34 00 00 7f 00 01 3f 00 00 ??...?44..?.??..

-102dB gives the correct output and register writes as well. (34h)

My regmap output maps correctly too. Weird.

So lets get a few versions of some things to see what and where things went wrong.

What kernel version? Alsa-lib version? What distro are you using?

Thanks, Brian