From patchwork Mon Aug 8 17:10:20 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 1046062 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p78HBk7p003772 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 8 Aug 2011 17:12:07 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QqTMU-0004tE-Og; Mon, 08 Aug 2011 17:11:35 +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 1QqTMT-0003uC-Vn; Mon, 08 Aug 2011 17:11:33 +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 1QqTLY-0003bz-Sl for linux-arm-kernel@lists.infradead.org; Mon, 08 Aug 2011 17:10:38 +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 p78H9x13020580; Mon, 8 Aug 2011 18:09:59 +0100 (BST) From: Will Deacon To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 2/6] ARM: realview: ensure visibility of writes during reset Date: Mon, 8 Aug 2011 18:10:20 +0100 Message-Id: <1312823424-9654-3-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: <1312823424-9654-1-git-send-email-will.deacon@arm.com> References: <1312823424-9654-1-git-send-email-will.deacon@arm.com> X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110808_131037_188937_2AD60F83 X-CRM114-Status: GOOD ( 12.90 ) X-Spam-Score: -3.1 (---) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (-3.1 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [217.140.96.50 listed in list.dnswl.org] -0.8 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain Cc: 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, 08 Aug 2011 17:12:07 +0000 (UTC) The various reset routines in mach-realview rely on an FPGA to power-cycle the board after writing some magic runes to memory-mapped registers. This patch adds a dsb() following the writes, so that they become visible before we mdelay(1000) in the arch_reset code. Without this patch, the timeout would expire sporadically, causing the reset to fail. Signed-off-by: Will Deacon --- arch/arm/mach-realview/include/mach/system.h | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/arm/mach-realview/include/mach/system.h b/arch/arm/mach-realview/include/mach/system.h index a30f2e3..6657ff2 100644 --- a/arch/arm/mach-realview/include/mach/system.h +++ b/arch/arm/mach-realview/include/mach/system.h @@ -44,6 +44,7 @@ static inline void arch_reset(char mode, const char *cmd) */ if (realview_reset) realview_reset(mode); + dsb(); } #endif