From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752836Ab2AZVI3 (ORCPT ); Thu, 26 Jan 2012 16:08:29 -0500 Received: from moutng.kundenserver.de ([212.227.17.8]:53795 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751854Ab2AZVI2 (ORCPT ); Thu, 26 Jan 2012 16:08:28 -0500 Date: Thu, 26 Jan 2012 22:07:50 +0100 (CET) From: Guennadi Liakhovetski X-X-Sender: lyakh@axis700.grange To: Sascha Hauer cc: linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org, linux-sh@vger.kernel.org, Vinod Koul , Magnus Damm , Yoshihiro Shimoda , linux-mmc@vger.kernel.org, Paul Mundt , linux-serial@vger.kernel.org Subject: Re: [alsa-devel] [PATCH 1/7 v2] dmaengine: add a simple dma library In-Reply-To: <20120126173444.GM5446@pengutronix.de> Message-ID: References: <1327589784-4287-1-git-send-email-g.liakhovetski@gmx.de> <1327589784-4287-2-git-send-email-g.liakhovetski@gmx.de> <20120126173444.GM5446@pengutronix.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Provags-ID: V02:K0:jd5aGejw5its88DdcsaS3POCGlE+LThz/8ge31SqRJJ Z9DBLAKjLDss4K+AYV+RRPNnVPZNQX+VxpW4jWWjOoAGCQ/R6/ 19o22b3+TLAlrnMaS2jbMuVm0qLdtI9im7Gw0X4YhnFMsVZd2y bxRLqkpWgicMHEHoLf9rkfqqa+IG0vCFXXLR8vsY7tkZhMQ3f1 UPHvBpYEHJwSewkmpNyA4eNzl5wQbLBtwZCVZ2MghP0U5pNTbd bXhB2axgg29giTvHI+6/mCuV6VXhfRlrQP6hrxxhsHyJu4Kcqy x0jCon+MeH8ALRm4S5nvoE4PLvurlMcxlMcvsnD/AxKKUK8cdg KJw9guRIi7jKaVZNyScPL4xdpjCsK6gicCkBSE6lueQlClFw4G iour0wi6V68QQ== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Sascha On Thu, 26 Jan 2012, Sascha Hauer wrote: > Hi Guennadi, > > On Thu, Jan 26, 2012 at 03:56:18PM +0100, Guennadi Liakhovetski wrote: > > This patch adds a library of functions, helping to implement dmaengine > > drivers for hardware, unable to handle scatter-gather lists natively. > > The first version of this driver only supports memcpy and slave DMA > > operation. > > > > Signed-off-by: Guennadi Liakhovetski > > --- > > > > [...] > > > + > > +/* > > + * For slave DMA we assume, that there is a finite number of DMA slaves in the > > + * system, and that each such slave can only use a finite number of channels. > > + * We use slave channel IDs to make sure, that no such slave channel ID is > > + * allocated more than once. > > + */ > > +static unsigned int slave_num = 256; > > +module_param(slave_num, uint, 0444); > > + > > +/* A bitmask with slave_num bits */ > > +static unsigned long *simple_slave_used; > > You never check that the slave ids passed into this code are > within the range of slave_num. Given that this is a user changeable > value this is a bit flawy. Right, never trust the user;-) I'll fix that. Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/