Subject: Re: [PATCH 3/3] powernv:idle: Set LPCR_UPRT on wakeup from deep-stop

From: Benjamin Herrenschmidt <[email-masked]>
Date: Thu, 13 Apr 2017 14:12:05 +1000

On Thu, 2017-04-13 at 09:28 +0530, Aneesh Kumar K.V wrote:
> >   #endif
> >        mtctr   r12
> >        bctrl
> > +/*
> > + * cur_cpu_spec->cpu_restore would restore LPCR to a
> > + * sane value that is set at early boot time,
> > + * thereby clearing LPCR_UPRT.
> > + * LPCR_UPRT is required if we are running in Radix mode.
> > + * Set it here if that be the case.
> > + */
> > +BEGIN_MMU_FTR_SECTION
> > +     mfspr   r3, SPRN_LPCR
> > +     LOAD_REG_IMMEDIATE(r4, LPCR_UPRT)
> > +     or      r3, r3, r4
> > +     mtspr   SPRN_LPCR, r3
> > +END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)

We are probably better off saving the value somewhere during boot
and just "blasting" it whole back.

Cheers
Ben.