DSS and USBHOST powerdomains not entering low-power states on 37xx EVM

[Paul Walmsley]

Hi Kevin,

On Mon, 6 Aug 2012, Kevin Hilman wrote:

> Is this only happening on this 37xx platform?    Just curious, because
> it seems to be a problem on any OMAP3xxx SoC.

So far I've only run the baseline tests on 37xx, so wanted to state only 
what was observed here.

> ...it must be the usecounts that are not being updated.  This seems to
> be a side effect of the pre/post transition optimization I did.  A quick
> hack seems to indicate that that's indeed the case[1].  By default,
> omap_sram_idle() is now only calling the pre/post callbacks for MPU,
> NEON, PER, and CORE, and only if those domains are transitioning, so any
> other domains not explicitly managed by the idle path have lots their
> usecounting.  Oops.
> 
> I guess Tero's usecounting series should fix this up.

Thanks for the diagnosis.  Care to put together a patch to fix this for 
v3.6-rc?  The earliest point that the usecounting improvements could get 
in would be v3.7.  This problem is breaking the PM regression tests here 
that parse the powerdomain state count fields.


- Paul