[U-Boot] [U-Boot,PATCHv4] Optimized nand_read_buf for kirkwood

Scott Wood scottwood at freescale.com
Fri Nov 15 00:59:12 CET 2013


On Thu, 2013-11-14 at 09:18 +0100, Holger Brunck wrote:
> Hi Scott,
> 
> On 11/14/2013 02:31 AM, Scott Wood wrote:
> > On Mon, Aug 26, 2013 at 02:10:56PM +0200, Phil Sutter wrote:
> >> From: Nico Erfurth <ne at erfurth.eu>
> >>
> >> 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 <ne at erfurth.eu>
> >> Tested-by: Phil Sutter <phil.sutter at viprinet.com>
> >> Cc: Prafulla Wadaskar <prafulla at marvell.com>
> >>
> >> ---
> >> 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.
> > 
> 
> it's not in board specific code defined it's defined in a common kirkwood header:
> 
> arch/arm/include/asm/arch-kirkwood/config.h:58:#define CONFIG_NAND_KIRKWOOD

Oops.  I thought I grepped the whole tree rather than just include/, but
apparently not.

-Scott





More information about the U-Boot mailing list