Status of Intel HDA powersave mode for Maverick

[Chase Douglas]

On Fri, 2010-05-28 at 08:42 -0400, Daniel Chen wrote:
> > What's the status of Intel HDA powersave mode? In Lucid, when the mode
> > is enabled we hear popping as the chip powers on. Will this be resolved
> > for Maverick?
> 
> That symptom is largely dependent on the specific controller and codec
> combination. It should be resolved for the Intel+Sigmatel/IDT
> combination; NVidia+Conexant/Analog Devices/etc. are not as
> well-tested. As I mentioned in the channel yesterday, we likely need
> to sleep longer in the driver to allow for dissipation to occur, which
> may mean reverting a patch [that reverts an earlier patch to sleep
> longer!].

I've got a macbook 5,1 with an nVidia MCP chip. Is this one setup you
need further testing on? I'd be happy to help you out here.

> In short, I'd put forth that we have a decent chance to get this issue
> sorted for Maverick, but it likely will mean carrying patches that are
> not in 2.6.35.

I think if we can get these in soon, then that's not a big problem. As
long as they are in with enough time for testing before release. Though
this really is up to Leann :).

> > I'm working on the pm-utils-powersave-policy scripts, and I've been
> > working under the assumption that this would be fixed for Maverick. Then
> > we would just enable it by default at all times and drop the policy
> > script that currently enables powersave mode when we go to battery
> > power.
> 
> We (well, I) tried this back in Karmic, and the state is nominally
> better now: Intel+Sigmatel/IDT are well-supported, but there are other
> combinations. We should have a better idea by the beginning of August
> (prior to Release Development Iteration three planning according to
> the Maverick release schedule) whether it is feasible to enable
> powerdown by default for all combinations.

Might I suggest we remove the policy and ask people to test on
ubuntu-devel? We can throw the policy back in if we get bad results.
There are some devs who seem to want the policy killed anyways, even if
we don't enable powersave by default. They don't want popping at all,
even just on battery power. I'm not in that group, but they wouldn't
mind getting rid of this I think.

-- Chase