From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Wood Date: Wed, 13 Nov 2013 19:31:02 -0600 Subject: [U-Boot] [U-Boot,PATCHv4] Optimized nand_read_buf for kirkwood In-Reply-To: <1377519056-25364-1-git-send-email-phil.sutter@viprinet.com> References: <1377519056-25364-1-git-send-email-phil.sutter@viprinet.com> Message-ID: <20131114013102.GA12213@home.buserror.net> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Mon, Aug 26, 2013 at 02:10:56PM +0200, Phil Sutter wrote: > From: Nico Erfurth > > The basic idea is taken from the linux-kernel, but further optimized. > > First align the buffer to 8 bytes, then use ldrd/strd to read and store > in 8 byte quantities, then do the final bytes. > > Tested using: 'date ; nand read.raw 0xE00000 0x0 0x10000 ; date'. > Without this patch, NAND read of 132MB took 49s (~2.69MB/s). With this > patch in place, reading the same amount of data was done in 27s > (~4.89MB/s). So read performance is increased by ~80%! > > Signed-off-by: Nico Erfurth > Tested-by: Phil Sutter > Cc: Prafulla Wadaskar > > --- > Changed since V3: > - fixed author > --- > drivers/mtd/nand/kirkwood_nand.c | 32 ++++++++++++++++++++++++++++++++ > 1 file changed, 32 insertions(+) I tried to build-test this, and I couldn't find any board that defines CONFIG_NAND_KIRKWOOD. The patch that removed it was commit b5befd8211b54ae2d2fca3fbed061c879951ceaa ("arm/km: fix u-boot.kwb build breakage"), over two years ago. It's not clear whether the removal was intentional. What target did you use to test this? -Scott