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Message-ID: <1322510511.23348.40.camel@pasglop>
Subject: Re: [PATCH 1/6] powerpc/time: Handle wrapping of decrementer
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Scott Wood <scottwood@freescale.com>
Date: Tue, 29 Nov 2011 07:01:51 +1100
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References: <20111124060716.362614789@samba.org>
 <20111124060847.105131188@samba.org> <4ED3C875.5050002@freescale.com>
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Cc: johnstul@us.ibm.com, linuxppc-dev@lists.ozlabs.org, paulus@samba.org,
 Anton Blanchard <anton@samba.org>, miltonm@bga.com
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On Mon, 2011-11-28 at 11:44 -0600, Scott Wood wrote:
> > -#ifndef CONFIG_BOOKE
> > -     /* On server, re-trigger the decrementer if it went negative since
> > -      * some processors only trigger on edge transitions of the sign bit.
> > -      *
> > -      * BookE has a level sensitive decrementer (latches in TSR) so we
> > -      * don't need that
> > +     /*
> > +      * Trigger the decrementer if we have a pending event. Some processors
> > +      * only trigger on edge transitions of the sign bit. We might also
> > +      * have disabled interrupts long enough that the decrementer wrapped
> > +      * to positive.
> >        */
> > -     if ((int)mfspr(SPRN_DEC) < 0)
> > -             mtspr(SPRN_DEC, 1);
> > -#endif /* CONFIG_BOOKE */
> > +     decrementer_check_overflow();
> 
> Where did the #ifndef CONFIG_BOOKE go?  BookE doesn't need this; the
> interrupt will continue asserting until software clears TSR[DIS].

Ooops, I didnt notice Anton was removing it. Please send me a followup
patch to make decrementer_check_overflow() an empty inline on BookE.

Cheers,
Ben.