On Fri, 31.08.07 17:50, DSK (dsk.in.2007 at gmail.com) wrote: Hi! > I can see that module-detect after loading module-alsa-sink sends out > zeroes to the sound card ( snd_pcm_writei )even when there is no client > attached to the daemon yet .. > > Doesnt this consumes CPU cycles unnecessarily.. > Can't we do away with this ?? > > I agree that this feature is available in autoloaded modles but then why > does Pulseaudio has to write zeroes when its module(module-alsa-sink) is > simply loaded using module-detect? The primary reason for this is that most audio drivers produce relative loud crackling noises when you open or close them. Upstream ALSA is now working on minimizing these issues, but currently you get those even with the newest intel-hda drivers. OTOH keeping the devices open is indeed detrimental for power consumption and hence PA from SVN (lennart branch, the upcoming 0.9.7) now features a new module "module-suspend-on-idle" which will suspend all devices when they are idle for too long. For the ALSA case this means that the device is closed when idle. So, if you want to save power and have sane sound drivers+hardware, load that module. If you don't care about power consumption or care about those crackling noises, don't load them. The default config will now load it. Lennart -- Lennart Poettering Red Hat, Inc. lennart [at] poettering [dot] net ICQ# 11060553 http://0pointer.net/lennart/ GnuPG 0x1A015CC4
