From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Gelinske Date: Fri, 15 Jan 2010 17:51:38 -0800 (PST) Subject: [U-Boot] [PATCH RFC] NAND: Improve read performance from Large Page NAND devices In-Reply-To: <4B1F8D70.5070105@ge.com> References: <4B1E71D9.6080802@ge.com> <20091208220602.8796A19F3F@gemini.denx.de> <20091209110222.2AC613F6CC@gemini.denx.de> <4B1F8D70.5070105@ge.com> Message-ID: <27186018.post@talk.nabble.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de What kind of CPU usage are you seeing? I am throughput of ~1.9MBs for writes on a Samsung K9WBG08U1M 4GB with 4K page but with high cpu usage. Nick Thompson-9 wrote: > > On 09/12/09 11:02, Wolfgang Denk wrote: >> Dear Nick Thompson, >> >> In message <4B1E71D9.6080802@ge.com> you wrote: >>> Improve read performance from Large Page NAND devices. >>> >>> This patch produces a ~31% improvement in oob_first read speed (on a >>> 300MHz ARM9). The time for a mid-buffer 2k page read is now 293us, >>> 6.99MB/s (was 385us, 5.31MB/s). oob_first is probably the best case >>> improvement. >>> >>> Signed-off-by: Nick Thompson >> >> Also tested on Canyonlands (460EX); here I actually see a slightj >> improvement (5.5% faster, i. e. time to read 126 MB from NAND goes >> down from 28.8 to 27.2 seconds (4.4 -> 4.6 MiB/s). >> >> Tested-by: Wolfgang Denk > > Hi Wolfgang, > > Thanks again. > > It seems the raw page data transfer rate is quite low on that board. > The patch saves time between page data transfers, so the percentage > improvement seen is better if you can get the page data out quicker. > > The default read_buf (and write_buf) in nand_base.c are safe, but slow. > I put in davinci specific optimised versions (DMA or multibyte read > ticks might be used) to double my raw transfer rate. Without that, my > measurements would show ~15% improvement only. > > In total on da830evm I'm getting a >300% speed improvement. 1.69MB/s > changes to 6.99MB/s. (5.31MB/s without this patch.) > > Nick. > _______________________________________________ > U-Boot mailing list > U-Boot at lists.denx.de > http://lists.denx.de/mailman/listinfo/u-boot > > -- View this message in context: http://old.nabble.com/-U-Boot---PATCH-RFC--NAND%3A-Improve-read-performance-from-Large-Page%09NAND-devices-tp26695701p27186018.html Sent from the Uboot - Users mailing list archive at Nabble.com.