From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [PATCH 02/12] powermac: support G5 CPU hotplug Date: Fri, 09 Feb 2007 09:24:03 +1100 Message-ID: <1170973443.2620.371.camel@localhost.localdomain> References: <20070207124536.963531000@sipsolutions.net> <20070207124610.392302000@sipsolutions.net> <1170940494.4385.51.camel@johannes.berg> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1170940494.4385.51.camel@johannes.berg> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.osdl.org Errors-To: linux-pm-bounces@lists.osdl.org To: Johannes Berg Cc: linuxppc-dev@ozlabs.org, linux-pm@lists.osdl.org List-Id: linux-pm@vger.kernel.org On Thu, 2007-02-08 at 14:14 +0100, Johannes Berg wrote: > On Wed, 2007-02-07 at 13:45 +0100, Johannes Berg wrote: > = > > Except for the in-irq count hack I'm happy with this. I still haven't f= ound > > where the in-hard-irq count is set to 1 in the down path during suspend= or > > resume and other platforms do similar things so I'm inclined to leave t= his. > = > Um, ok, so the hack breaks platforms that don't have paca, e.g. chrp32. > = > Also, I finally figured out how the in-hard-irq count happens. The thing > is that when I try to turn off the CPU it actually doesn't really turn > off of course, so it ends up doing NAP and taking timer interrupts... > which goes irq_enter() and we happen to kill it afterwards. > = > I have two ways of fixing this: > - just ignore it as we do now > - insert a "if (cpu_dead) return" into the timer interrupt function > = > I prefer the latter because then we're guaranteed that whatever the > timer interrupt does we don't modify any state for/by the CPU that isn't > supposed to exist. Agreed. Ben.