From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750761AbWLPKbx (ORCPT ); Sat, 16 Dec 2006 05:31:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753584AbWLPKbx (ORCPT ); Sat, 16 Dec 2006 05:31:53 -0500 Received: from mtagate3.uk.ibm.com ([195.212.29.136]:53523 "EHLO mtagate3.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750761AbWLPKbw (ORCPT ); Sat, 16 Dec 2006 05:31:52 -0500 Subject: Re: [S390] Fix reboot hang on LPARs From: Martin Schwidefsky Reply-To: schwidefsky@de.ibm.com To: Heiko Carstens Cc: linux-kernel@vger.kernel.org, holzheu@de.ibm.com In-Reply-To: <20061215211558.GA8101@osiris.ibm.com> References: <20061215162218.GF4920@skybase> <20061215211558.GA8101@osiris.ibm.com> Content-Type: text/plain Organization: IBM Corporation Date: Sat, 16 Dec 2006 11:31:39 +0100 Message-Id: <1166265099.26640.13.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2006-12-15 at 22:15 +0100, Heiko Carstens wrote: > This is broken. pgm_check_occured must be volatile, otherwise the -EIO path > in stsch_reset might get optimized away. That is true, good spotting. Only adding a "volatile" in not the right solution. The point here is that the stsch inline assembly can write to pgm_check_occured. We better tell the compiler, e.g. by adding a "memory" clobber or better a "+m" (pgm_check_occured). For the later we'd have to copy the inline assembly though. -- blue skies, Martin. Martin Schwidefsky Linux for zSeries Development & Services IBM Deutschland Entwicklung GmbH "Reality continues to ruin my life." - Calvin.