On Mon, Oct 07, 2013 at 10:22:42AM -0700, Patrick Lai wrote:
Lately, there has been a lot of emphasis on reducing cold start latency which audio hardware path setup takes up good chunk of time. I found DAPM takes up quite a bit of time finding path to enable. In addition,
What are the problems you're seeing here? This used to be a big problem for modern CODECs with big sets of widgets and routes but the optimisations I did a while back (which made it into v3.4 so I think everyone is using them now) and the work that Tsutsui-san did in v3.10 on improving the graph reset got it reasonably under control for the systems that I was aware of having trouble.
The commits from Tsutsui-san were:
0e669246dcd1 ASoC: dapm: Remove redundant clear_walk() for supply widgets 1059ecfa0f1e ASoC: dapm: Only clear paths we've walked
(mainly the second one).
DPCM could be enhanced to save on cold start latency by enabling front-end & back-end in parallel if underlying hardware can support it.
Hrm, nobody mentioned any problems with CPU side startup times previously. What exactly is taking the time with this stuff - is it something that could be pushed into DAPM and use what's there already (or alternatively then be optimised and used for CODECs too)?
I would like to see if we can have some discussion on optimization.
Well volunteered :)