MUSB peripheral DMA regression caused by driver core runtime PM change

[Tony Lindgren]

* Alan Stern <stern at rowland.harvard.edu> [151023 13:34]:
> On Fri, 23 Oct 2015, Tony Lindgren wrote:
> 
> > > Thus the sequence of events should be:
> > > 
> > > 	Allocate the musb device;
> > > 	Runtime-enable the omap2430 (since it is now safe to do so);
> > > 	Runtime-enable the musb and declare it irq_safe (this will
> > > 		automatically runtime-resume the omap2430);
> > > 	Register the musb.
> > > 
> > > If things are done this way, no special action needs to be taken.
> > 
> > Yes good point, that requires changing the init for the whole
> > drivers/musb though.
> 
> This will have to be done anyway, since the way it is now (if I 
> understand correctly), the musb is registered and made available to 
> userspace before its parent is operational (i.e., at full power).

Yes I agree.

> > Also, we should reorganize the whole musb and make
> > the platform glue and musb core drivers completely separate using a
> > shared interrupt where needed.
> > 
> > For the regression for the -rc series? Do you see any better
> > alternatives to what I posted?
> 
> No.

OK thanks,

Tony