From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: [PATCH 00/10] AXFS: Advanced XIP filesystem Date: Mon, 15 Sep 2008 17:40:12 +0100 Message-ID: <20080915164012.GB13631@shareable.org> References: <48AD00C4.6060302@gmail.com> <20080821110749.GA1926@shareable.org> <6934efce0808210711t686a88eci6eb294dbb54d68fe@mail.gmail.com> <48AE0476.80109@snapgear.com> <20080822181314.GB24179@shareable.org> <6934efce0808221116w76a662b0t954b0922b69d3232@mail.gmail.com> <20080822183713.GC24179@shareable.org> <6934efce0809121317r418c80e8s4755669cc74975c4@mail.gmail.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <6934efce0809121317r418c80e8s4755669cc74975c4@mail.gmail.com> Sender: linux-embedded-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jared Hulbert Cc: Greg Ungerer , Linux-kernel@vger.kernel.org, linux-embedded@vger.kernel.org, linux-mtd , =?iso-8859-1?Q?J=F6rn?= Engel , tim.bird@am.sony.com, cotte@de.ibm.com, nickpiggin@yahoo.com.au Jared Hulbert wrote: > > I think the "fast" in "fast synchronous" gives it away :-) > > Yes, I suppose it does. > > > I'm using Spansion MirrorBit S29GL128N, which reads at about 0.6 MByte/s. > > I think you should get more like an order of magnitude higher.... Get > an expert to look at your timings in the bootloader. Make sure things > are cached too. ioremap_cached()... Yes, looking at the Spansion datasheet, if it were interfaced properly it should be quite fast. (25ns access time for in-page 16-bit reads, 100ns for random reads). I'll see if ioremap_cached() makes a difference to streaming read performance. The BSP suppliers have been quite cautious in places, flushing cache a bit too often. (I'm not surprised - we had disk ext3 filesystem corruption due to insufficient cache flushing in places too.) > > Oh, and it's a 166MHz ARM, so it's quite capable of decompressing > > faster than the NOR can deliver. > > Depends on how you are measuring it. You ought to be able to get at > least 2 orders of magnitude higher read speeds with a good sync Flash. > Some of the newer stuff is even faster. Thanks. Oh, how I look forward to the day of working with current kernels and current hardware. -- Jamie