Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161184AbXBUKA1 (ORCPT ); Wed, 21 Feb 2007 05:00:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161187AbXBUKA1 (ORCPT ); Wed, 21 Feb 2007 05:00:27 -0500 Received: from mtagate3.de.ibm.com ([195.212.29.152]:13064 "EHLO mtagate3.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161184AbXBUKAX (ORCPT ); Wed, 21 Feb 2007 05:00:23 -0500 Date: Wed, 21 Feb 2007 11:00:22 +0100 From: Martin Schwidefsky To: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Subject: [S390] prevent softirqs if delay is called disabled Message-ID: <20070221100022.GB13419@skybase> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2237 Lines: 64 From: Martin Schwidefsky [S390] prevent softirqs if delay is called disabled The new delay implementation uses the clock comparator and an external interrupt even if it is called disabled for interrupts. To do this all external interrupt source except clock comparator are switched of before enabling external interrupts. The external interrupt at the end of the delay period may not execute softirqs or we can end up in a dead-lock. Signed-off-by: Martin Schwidefsky --- arch/s390/lib/delay.c | 7 +++++++ 1 files changed, 7 insertions(+) diff -urpN linux-2.6/arch/s390/lib/delay.c linux-2.6-patched/arch/s390/lib/delay.c --- linux-2.6/arch/s390/lib/delay.c 2007-02-21 10:47:06.000000000 +0100 +++ linux-2.6-patched/arch/s390/lib/delay.c 2007-02-21 10:47:23.000000000 +0100 @@ -15,6 +15,7 @@ #include #include #include +#include void __delay(unsigned long loops) { @@ -35,7 +36,11 @@ void __udelay(unsigned long usecs) { u64 end, time, jiffy_timer = 0; unsigned long flags, cr0, mask, dummy; + int irq_context; + irq_context = in_interrupt(); + if (!irq_context) + local_bh_disable(); local_irq_save(flags); if (raw_irqs_disabled_flags(flags)) { jiffy_timer = S390_lowcore.jiffy_timer; @@ -62,6 +67,8 @@ void __udelay(unsigned long usecs) __ctl_load(cr0, 0, 0); S390_lowcore.jiffy_timer = jiffy_timer; } + if (!irq_context) + _local_bh_enable(); set_clock_comparator(S390_lowcore.jiffy_timer); local_irq_restore(flags); } -- blue skies, IBM Deutschland Entwicklung GmbH Martin Vorsitzender des Aufsichtsrats: Johann Weihen Gesch?ftsf?hrung: Herbert Kircher Martin Schwidefsky Sitz der Gesellschaft: B?blingen Linux on zSeries Registergericht: Amtsgericht Stuttgart, Development HRB 243294 "Reality continues to ruin my life." - Calvin. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/