From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Ujfalusi Subject: Re: [PATCH 1/2] OMAP: DMA: prevent races while setting M idle mode to nostandby Date: Wed, 1 Dec 2010 14:21:34 +0200 Message-ID: <201012011421.34412.peter.ujfalusi@nokia.com> References: <20101130132341.13286.25157.sendpatchset@ahunter-work.research.nokia.com> <20101130132347.13286.40388.sendpatchset@ahunter-work.research.nokia.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.nokia.com ([147.243.1.47]:40547 "EHLO mgw-sa01.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751900Ab0LAMWA (ORCPT ); Wed, 1 Dec 2010 07:22:00 -0500 In-Reply-To: <20101130132347.13286.40388.sendpatchset@ahunter-work.research.nokia.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Hunter Adrian (Nokia-MS/Helsinki)" Cc: Tony Lindgren , Manjunatha GK , Santosh Shilimkar , linux-omap Mailing List On Tuesday 30 November 2010 15:23:47 Hunter Adrian (Nokia-MS/Helsinki) wrote: > From 8c0f4490d93b67326ff24f6ce1c7e925b08d96b3 Mon Sep 17 00:00:00 2001 > From: Adrian Hunter > Date: Mon, 22 Nov 2010 11:32:48 +0200 > Subject: [PATCH 1/2] OMAP: DMA: prevent races while setting M idle mode to > nostandby > > In a couple of OMAP errata cases, sDMA M idle mode must be > set temporarily to nostandby. If two DMA users were to do > that at the same time, a race condition would arise. > Prevent that by using a spin lock and counting up/down the > number of times nostandby is set/reset. > > Signed-off-by: Adrian Hunter Acked-by: Peter Ujfalusi