From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp121.sbc.mail.sp1.yahoo.com ([69.147.64.94]) by bombadil.infradead.org with smtp (Exim 4.68 #1 (Red Hat Linux)) id 1Jhv2X-0004NJ-0D for linux-mtd@lists.infradead.org; Fri, 04 Apr 2008 23:09:45 +0000 From: David Brownell To: linux-arm-kernel@lists.arm.linux.org.uk Subject: Re: [PATCH] jffs2 summary allocation Date: Fri, 4 Apr 2008 16:09:40 -0700 References: <713171.37644.qm@web26213.mail.ukl.yahoo.com> <20080404124812.d39fa640.akpm@linux-foundation.org> In-Reply-To: <20080404124812.d39fa640.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200804041609.41092.david-b@pacbell.net> Cc: linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, Michael Trimarchi , spi-devel-general@lists.sourceforge.net, Andrew Morton , dwmw2@infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Friday 04 April 2008, Andrew Morton wrote: > I'm assuming from the trace that the arm code tried to put that memory > under DMA (or at least, passed it into part of the DMA management code to > get the various caches sorted out) and that the arm DMA support code > doesn't like being given vmalloced memory. Actually, Documentation/DMA-Mapping.txt has a section right up front called "What memory is DMA'able?" ... which despite its ungrammatical title, says clearly: ... This means specifically that you may _not_ use the memory/addresses returned from vmalloc() for DMA. ... So I'm rather surprised to see *ANY* kernel code trying to do that. That rule has been in effect for many, many years now. - Dave