[pulseaudio-discuss] PulseAudio gives an assertion error when attempting to load with a USB sound card connected.

Lennart Poettering lennart at poettering.net
Mon Sep 15 06:12:05 PDT 2008

On Mon, 15.09.08 15:59, Luke Yelavich (themuso at ubuntu.com) wrote:


> I: module-alsa-sink.c: Volume ranges from 0 to 255.
> I: module-alsa-sink.c: Volume ranges from 0.00 dB to 0.00 dB.
> E: module-alsa-sink.c: Assertion 'u->hw_dB_min < u->hw_dB_max' failed at modules/module-alsa-sink.c:1463, function module_alsa_sink_LTX_pa__init(). Aborting.

This is a driver error. The sound card claims to have 256 volume
levels, but the dB range is from 0 to 0 dB.

Most likely the USB device exports invalid volume range data, and ALSA
just passes this along. ALSA should not do that, it should simply
admit that the dB data it has is invalid and not pass this invalid
information on.

Please bring this up on alsa-devel and ask them to make a few very
basic validity checks for the dB data and ignore it if it fails these

I could work around this in PA too. However I believe the right
place for a fix for this is ALSA, not PA.


Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net         ICQ# 11060553
http://0pointer.net/lennart/           GnuPG 0x1A015CC4

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