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Feature #213

closed

Verify sound support is enabled in kernel

Added by Hammel over 10 years ago. Updated about 10 years ago.

Status:
Closed
Priority:
Urgent
Assignee:
Category:
04 - Root File System
Target version:
Start date:
14 Aug 2013
Due date:
% Done:

100%

Estimated time:
Severity:
04 - Low

Description

The kernel driver is snd-bcm2835. This is compiled as a loadable module, so needs to be loaded at boot time.

Also, tools to test sound are missing from buildroot's config:
  1. aplay
  2. speaker-test
  3. amixer
    See eLinux RPi Sound info
Actions #1

Updated by Hammel over 10 years ago

  • Status changed from New to In Progress
  • % Done changed from 0 to 20

Enabled alsa utilities for testing sound in buildroot config. Changes tested in build and pushed upstream.

Actions #2

Updated by Hammel over 10 years ago

  • % Done changed from 20 to 50

Sound seems to work if you load that module. I'm not quite sure how to load the module other than through an init script. I could write one, but shouldn't there be an /etc/modules.conf or similar? Maybe /etc/modprobe.conf or /etc/modprobe.d/*.conf?

Actions #3

Updated by Hammel over 10 years ago

The problem seems to be that the Busybox config enabled Simplified Modutils which doesn't use /etc/modules.conf. It can use /etc/modules/<module_name> but it's unclear how to use that at the moment. I'm still researching it.

Barring finding more info on the format of those module config files I'll have to write an init script to load the sound drivers. I could just add a section to S01mdev to handle it, which might be easier (just parse /etc/modules.conf, perhaps).

Actions #4

Updated by Hammel over 10 years ago

  • Target version changed from 1.0 - Atreides to 2.0 - Harkonnen
Actions #5

Updated by Hammel over 10 years ago

  • Priority changed from Urgent to Normal
Actions #6

Updated by Hammel over 10 years ago

  • Priority changed from Normal to Urgent
  • Target version changed from 2.0 - Harkonnen to 0.8.0
  • Severity changed from 03 - Medium to 04 - Low
Actions #7

Updated by Hammel about 10 years ago

  • Status changed from In Progress to Closed
  • % Done changed from 50 to 100

Verified the sound drivers are being loaded with the recently added rc.modules init script (via S00dev).

Tested audio playback on PiBox 0.7.0 with
aplay classical-clip.wav
where the clip was a 35 second clip from the Jurassic Park Theme (from the soundtrack). I used Altec Lansign speakers (front left/right and woofer). The sound only came out of the woofer. So I tried it with headphones and it sounded fine though a little muffled. I suspect a better audio mixer would help, but for now this is fine. I at least know sound is working.

This issue can be closed.

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