Hi, As with David's campaign to fix up some volume issues, I was able to hijack a thread of his on alsa-devel to discuss issues relating to my own volume quirks. For a long time, if my volume went below 16% (ish, technically @ -46.5dB and below) it was effectively muted. As it turns out my h/w is misbehaving. The HDA specs (apparently) state that a slider should not mute things when set to 0, and rather use a separate mute switch. For my hardware, this was fixed by the following kernel patch: http://permalink.gmane.org/gmane.linux.alsa.devel/77644 This TLV fix does not actually solve the issue, but it does report it correctly. Sadly this didn't seem to make any difference by itself, so I dug a little deeper. PA uses snd_mixer_selem_set_playback_dB() to set the volume. It uses a dir argument of +1 to request to alsa "please don't go lower than I request" (i.e. round up). Sadly the function in alsa-lib that deals with this did not check for the "min is mute" TLV flag and thus happily set the volume to min (and thus mute) when we wanted a volume less than -46.5dB. So the following patch to alsa-lib fixes this problem: http://permalink.gmane.org/gmane.linux.alsa.devel/77693 So I now have a properly working volume range \o/ I expect that any other hardware that makes use of this quirk will also suffer from the same problem and thus I would encourage distros to include the alsa-lib patch. Thanks to David and Clemens for help tracking this down. Col -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited [http://www.tribalogic.net/] Open Source: Mageia Contributor [http://www.mageia.org/] PulseAudio Hacker [http://www.pulseaudio.org/] Trac Hacker [http://trac.edgewall.org/]
