From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3vTsHD58ffzDq5W for ; Fri, 24 Feb 2017 11:22:00 +1100 (AEDT) Received: from localhost.localdomain (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id 3vTsHD1MqTz9s78 for ; Fri, 24 Feb 2017 11:22:00 +1100 (AEDT) Message-ID: <1487895722.16514.8.camel@neuling.org> Subject: Re: [PATCH] powerpc/xics: Adjust interrupt receive priority for offline cpus From: Michael Neuling To: Vaidyanathan Srinivasan Cc: linuxppc-dev@lists.ozlabs.org Date: Fri, 24 Feb 2017 11:22:02 +1100 In-Reply-To: <20170223105443.22029-1-svaidy@linux.vnet.ibm.com> References: <20170223105443.22029-1-svaidy@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2017-02-23 at 16:24 +0530, Vaidyanathan Srinivasan wrote: > Offline CPUs need to receive IPIs through XIVE when they are > in stop state and wakeup from that state. >=20 > Reduce interrupt receive priority in order to receive XIVE > wakeup interrupts when in offline state. >=20 > LOWEST_PRIORITY would allow all interrupts to be delivered > as wakeup events. This needs to be expanded to explain why "DEFAULT" doesn't work in this cas= e. This also needs an explicit statement that "It fixes onlining of CPUs on POWER9". I'd even advocate for making that the patch subject.=20 Also if it's the right fix, it needs a cc:stable. Mikey > Signed-off-by: Vaidyanathan Srinivasan > --- > =C2=A0arch/powerpc/sysdev/xics/xics-common.c | 2 +- > =C2=A01 file changed, 1 insertion(+), 1 deletion(-) >=20 > diff --git a/arch/powerpc/sysdev/xics/xics-common.c > b/arch/powerpc/sysdev/xics/xics-common.c > index 69d858e..c674a9d 100644 > --- a/arch/powerpc/sysdev/xics/xics-common.c > +++ b/arch/powerpc/sysdev/xics/xics-common.c > @@ -199,7 +199,7 @@ void xics_migrate_irqs_away(void) > =C2=A0 xics_set_cpu_giq(xics_default_distrib_server, 0); > =C2=A0 > =C2=A0 /* Allow IPIs again... */ > - icp_ops->set_priority(DEFAULT_PRIORITY); > + icp_ops->set_priority(LOWEST_PRIORITY); > =C2=A0 > =C2=A0 for_each_irq_desc(virq, desc) { > =C2=A0 struct irq_chip *chip;