RE: About the hibernation feature implementation in dwc3 driver

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> From: Felipe Balbi [mailto:balbi@xxxxxx]
> Sent: Tuesday, August 13, 2013 1:30 PM
> 
> On Tue, Aug 13, 2013 at 08:04:26PM +0000, Paul Zimmerman wrote:
> > > From: Felipe Balbi
> > > Sent: Tuesday, August 13, 2013 12:20 PM
> > >
> > > On Mon, Aug 05, 2013 at 03:41:57PM +0000, Wang, Yu Y wrote:
> > > > Hi Balbi,
> > > >
> > > > Please check the attached logs. The kernel base one kernel3.10.
> > >
> > > you didn't take the regdump after xHCI :-( I need to check if erst_base
> > > is being mirrored to DEPCMDPAR*
> >
> > Hi Felipe,
> >
> > There seems to be some basic misunderstanding here. ALL versions of the
> > Synopsys core share the internal RAM between device and host modes. So
> > the only supported way of switching modes is to shut down the driver for
> > the mode you are leaving, then start up the driver for the mode you are
> > entering and re-initialize (most of) the registers.
> >
> > This is described in the databook in the OTG -> Software Flow and OTG ->
> > Programming Model chapters.
> 
> sure.
> 
> > So whether a particular set of RAM-based registers is mirrored between
> > modes does not matter.
> 
> fair enough.
> 
> > And I don't see what this has to do with hibernation?
> 
> I have lost track of the conversation, probably. but I believe Yu
> mentioned resetting the IP everytime when coming out of hibernation and,
> for whatever reason, I confused myself with the other problem.

OK :)

By the way, I wanted to tell Yu that you (Felipe) are correct about not
resetting the core when coming out of hibernation. That is definitely
not required, and would probably break the resume from hibernation. I
think we (Synopsys) should update the databook to mention that
explicitly, since it is different from the normal initialization flow.

-- 
Paul

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