Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751069AbVJCPPB (ORCPT ); Mon, 3 Oct 2005 11:15:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751087AbVJCPPB (ORCPT ); Mon, 3 Oct 2005 11:15:01 -0400 Received: from ylpvm12-ext.prodigy.net ([207.115.57.43]:60819 "EHLO ylpvm12.prodigy.net") by vger.kernel.org with ESMTP id S1751057AbVJCPPA (ORCPT ); Mon, 3 Oct 2005 11:15:00 -0400 X-ORBL: [69.107.75.50] Date: Mon, 03 Oct 2005 08:14:57 -0700 From: David Brownell To: basicmark@yahoo.com, arjan@infradead.org Subject: Re: [RFC][PATCH] SPI subsystem Cc: linux-kernel@vger.kernel.org References: <20051003105748.213.qmail@web33014.mail.mud.yahoo.com> <1128337656.17024.10.camel@laptopd505.fenrus.org> In-Reply-To: <1128337656.17024.10.camel@laptopd505.fenrus.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <20051003151457.AD64FEE8CE@adsl-69-107-32-110.dsl.pltn13.pacbell.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 886 Lines: 24 > From: Arjan van de Ven > Date: Mon, 03 Oct 2005 13:07:36 +0200 > > please NEVER EVER do dma from or to a stack variable. It's not allowed > on all architectures and it is really really bad practice in general > anyway. Arjan, could you mention some Linuxes which don't allow it? Every time the topic of DMA to/from stack comes up, the advice is always to avoid it ... but so far as I recall, nobody's yet provided us with an example where it actually doesn't work. Failing such examples, it's normal to discount such dire warnings and just plan to apply the relevant minor tweaks if/when they're needed. - Dave - 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/