On Wednesday 13 May 2009 16:05:49 ext Mark Brown wrote: > On Wed, May 13, 2009 at 03:57:09PM +0300, Peter Ujfalusi wrote: > > Mark: About the power up and down sequences in the soc-dapm.c file: are > > they written in stone, or is it possible to make some - I think - minor > > modification to the sequences? > > The change you've made is to power the amplifiers down after the mixers. > That's going to cause problems on other systems - the result is going to > be that the amplifiers end up amplifying any noise the mixers make on > the way down which isn't good. There's bits of the sequence that can be > fairly readily reordered but I'd worry about that particular change. That is why I'm a bit nervous when I need to touch the core... It has been working fine for all other codes so far. In the twl4030 codec case, the playback involves the following chain in DAPM domain: Headset, PreDrive, Carkit, Earpiece: DAC -> PGA -> Mixer -> output pin. Handsfree: DAC -> PGA -> Mux -> output pin. While for example the WM9713 has it in this way: DAC -> Mixer -> PGA -> output pin While I was looking at the sequences, I wonder why the mux and mixer handled in a differently? I mean, that in power up the order is (simplified): mux -> dac -> mixer -> pga in power down: pga -> mixer -> dac -> mux Is it possible to add several SND_SOC_DAPM_PRE to the DAPM routing? For example to the HeadsetL, HeadsetR, HandsFreeL and HandsFreeR? How does it than would work? If this is possible, than I can handle the correct power up/down sequences required for the twl4030 codec. -- Péter _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
