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

[Phil Sutter <phil.sutter@viprinet.com>]

Scott,

On Wed, Nov 13, 2013 at 07:31:02PM -0600, Scott Wood wrote:
> On Mon, Aug 26, 2013 at 02:10:56PM +0200, Phil Sutter wrote:
> > From: Nico Erfurth <ne@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@erfurth.eu>
> > Tested-by: Phil Sutter <phil.sutter@viprinet.com>
> > Cc: Prafulla Wadaskar <prafulla@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.
> 
> 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?

I tested using a custom board with Marvell Kirkwood SoC, but e.g. the
Marvell OpenRD Ultimate should be fine.

Best wishes,

Phil Sutter
Software Engineer

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