From patchwork Mon Jun 6 17:04:53 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 852772 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter2.kernel.org (8.14.4/8.14.3) with ESMTP id p56H5pn3001158 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 6 Jun 2011 17:06:12 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QTdFF-0007OU-Dt; Mon, 06 Jun 2011 17:05:41 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QTdFE-0002Me-PX; Mon, 06 Jun 2011 17:05:40 +0000 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QTdEd-0002Eb-ET for linux-arm-kernel@lists.infradead.org; Mon, 06 Jun 2011 17:05:05 +0000 Received: from localhost.localdomain (e102144-lin.cambridge.arm.com [10.1.69.60]) by cam-admin0.cambridge.arm.com (8.12.6/8.12.6) with ESMTP id p56H3lFA004674; Mon, 6 Jun 2011 18:03:47 +0100 (BST) From: Will Deacon To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 1/6] ARM: l2x0: fix disabling function to avoid livelock Date: Mon, 6 Jun 2011 18:04:53 +0100 Message-Id: <1307379898-14256-2-git-send-email-will.deacon@arm.com> X-Mailer: git-send-email 1.7.0.4 MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1307379898-14256-1-git-send-email-will.deacon@arm.com> References: <1307379898-14256-1-git-send-email-will.deacon@arm.com> X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110606_130503_842895_5661F737 X-CRM114-Status: GOOD ( 13.25 ) X-Spam-Score: -0.0 (/) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (-0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain Cc: frank.hofmann@tomtom.com, Will Deacon X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Mon, 06 Jun 2011 17:06:13 +0000 (UTC) The l2x0_disable function attempts to writel with the l2x0_lock held. This results in livelock when the writel contains an outer_sync call for the platform. This patch replaces the writel with a call to writel_relaxed in the disabling code, preventing livelock from occurring. Signed-off-by: Will Deacon --- arch/arm/mm/cache-l2x0.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c index ef59099..2bce3be 100644 --- a/arch/arm/mm/cache-l2x0.c +++ b/arch/arm/mm/cache-l2x0.c @@ -266,7 +266,7 @@ static void l2x0_disable(void) unsigned long flags; spin_lock_irqsave(&l2x0_lock, flags); - writel(0, l2x0_base + L2X0_CTRL); + writel_relaxed(0, l2x0_base + L2X0_CTRL); spin_unlock_irqrestore(&l2x0_lock, flags); }