From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [patch 02/13] jffs2 summary allocation: don't use vmalloc() From: David Woodhouse To: David Brownell In-Reply-To: <20080730223924.3C51136129C@adsl-69-226-248-13.dsl.pltn13.pacbell.net> References: <200807301934.m6UJYvtA012276@imap1.linux-foundation.org> <20080730223924.3C51136129C@adsl-69-226-248-13.dsl.pltn13.pacbell.net> Content-Type: text/plain Date: Thu, 31 Jul 2008 08:33:03 +0100 Message-Id: <1217489583.3454.36.camel@pmac.infradead.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Cc: trimarchimichael@yahoo.it, jwboyer@gmail.com, linux-mtd@lists.infradead.org, akpm@linux-foundation.org, rmk@arm.linux.org.uk List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2008-07-30 at 15:39 -0700, David Brownell wrote: > > This patch will probably break all sorts of things because that buffer is > > &*large*: up to half a meg. > > > > So this patch isn't mergeable. I'll hang onto it to bug dmwm2 with when he > > reincarnates. > > I'm still asking whether MTD folk have any plans to make that stack DMA-safe... > more than just the SPI flash drivers (mtd_dataflash, m25p80) could benefit > from DMA support, so I'd hope it's at least being considered. > > If the answer is "no" then (a) the MTD interface specs need to finally say > they pass DMA-unsafe addresses, and (b) those SPI flash drivers are going > to need updates. Yes. We're planning to change the API so it looks a lot more like the block layer, and a lot less like the one we inherited from PCMCIA in the 1990s. One of the design considerations we've spoken about has been the fact that we want to make DMA work properly. -- dwmw2