2010/8/30 Takashi Iwai <tiwai@xxxxxxx> > At Sat, 28 Aug 2010 06:58:20 +0800, > Raymond Yau wrote: > > > > 2010/8/28 David Henningsson <david.henningsson@xxxxxxxxxxxxx> > > > > > 2010-08-27 17:43, Clemens Ladisch skrev: > > > > David Henningsson wrote: > > > >> So I've discovered that my sound card has a "PCM Playback Volume" > > > >> control, but changing that control does not alter the volume. > > > >> > > > >> Interestingly enough, this control does not come from the HDA > parser, it > > > >> is added by alsactl at boot time...! > > > > > > > > This control was created by the software volume plugin. When not > using > > > > this plugin, the control does not have any effect. > > > > > > > > To get rid of it, delete its entry from /etc/asound.state. > > > > > > Hmm, I wonder if this is an Ubuntu-specific bug then? Because when I > run > > > Maverick (the upcoming Ubuntu release) from a Live-CD, the "PCM > Playback > > > Volume" control is still there (and there is no asound.state, neither > in > > > /etc or in /var/lib/alsa). > > > When I use the plughw interface, the "PCM Playback Volume" does not > > > affect volume output. Should I use another device string to test the > > > softvol plugin, to see if it's there or not? > > > > > > > The softvol plugin it is defined in "front" device in > > /usr/share/alsa/cards/HDA-Intel.conf > > > > reason is some HDA codec does not has any hardware volume control > (analog) > > > > this user-defined control only effective when the application use "front" > > device > > Hm, but if PA opens the device with SND_PCM_NO_SOFTVOL flag, the > softvol should be skipped. > > AFAIK, PA did not use SND_PCM_NO_SOFTVOL and in "analog stereo duplex" profile , PA open "front" device for playback and capture which access the same "PCM Playback volume" control concurrently You can see the output of snd_pcm_dump() in the pulseraudio log still contain soffvol which is an indiication that PA did not use SND_PCM_NO_SOFTVOL the softvol control can only be distinguished using snd_ctl_elem_info_is_user() and there is no snd_mixer_* function to find out the softvol control since PA server use simple mixer api _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
