Hi, On Thu, Aug 18, 2022 at 3:19 PM Joseph S. Barrera III <joebar@xxxxxxxxxxxx> wrote: > > On 8/18/22 1:34 PM, Doug Anderson wrote: > > I tend to agree with Stephen's analysis. We actually need to keep the > > pullup enabled unless we are actually turning power off to the codec, > > which we don't seem to be doing. > > > > I guess I'm a little surprised that we don't even seem to turn any of > > this codec's regulators off in S3. That seems like it would be drawing > > power that we don't want. Maybe the "low power" mode of the codec is > > low enough and we need to avoid powering it off to avoid pops / hisses > > in S3 or something? If that's true, this might be one of those places > > where the "LPM" of the regulators might actually be useful... > > OK, fair enough, so suggestions on what I should do instead? Should I > look at why or how to turn the regulators off? Should I look into LPM? > Are there existing bugs for such work? It would be interesting to know from Judy if there's a reason we never turn the audio codec rails off. Maybe there's history that I'm not aware of? Matthias or Mengqi might also have ideas of how much power is at stake here? Ah, searching through the ChromeOS bug tracker finds some hits. At this point we should probably move the discussion off the lists and bring it back to the lists when we have some results. Unfortunately most of the bugs are not public and so having a discussion here is just noise for most people CCed. -Doug
