Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755357Ab1FFTtw (ORCPT ); Mon, 6 Jun 2011 15:49:52 -0400 Received: from mail-wy0-f174.google.com ([74.125.82.174]:50771 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753712Ab1FFTtv (ORCPT ); Mon, 6 Jun 2011 15:49:51 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=BAiTVa4uR1VxX+LfCmgXV7gkMgjdSfdtmPej7FTaFyiGeZ/A35p06cyzqpYKDzSBvF ZHqn7FYnCd6rgKBGGBh8ihua0u01z2vbDzptlwQNELIEliuxdK5l41HWqxuH9xxorWPM JqKdlRasisHUrH55Mzte2F5jkD6hhiSEi1HbU= Date: Mon, 6 Jun 2011 22:49:23 +0300 From: Dan Carpenter To: Geert Uytterhoeven Cc: anish , devel@driverdev.osuosl.org, arnd@arndb.de, lucas.demarchi@profusion.mobi, gregkh@suse.de, linux-kernel@vger.kernel.org, jic23@cam.ac.uk, manuel.stahl@iis.fraunhofer.de Subject: Re: [PATCH 1/2] staging: iio replaced kmalloc with local variables. Message-ID: <20110606194923.GC3846@shale.localdomain> References: <1307387257.4327.12.camel@anish-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 882 Lines: 22 On Mon, Jun 06, 2011 at 09:13:29PM +0200, Geert Uytterhoeven wrote: > On Mon, Jun 6, 2011 at 21:07, anish wrote: > > From: anish kumar > > > > Replace kmalloc with local variables as it was un-necessary and > > Is it really unnecessary? > Or is this hardware that cannot transfer buffers on the stack? > IIRC there have been similar problems with SCSI command buffers on the stack. Yes. You're right. These buffers are not allowed to be stack memory. The documentation is the section "What memory is DMA'able?" in Documentation/DMA-API-HOWTO.txt. regards, dan carpenter -- 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/