[flashrom] AAI on SST25VF016B

[Stefan Tauner]

On Fri, 29 Jul 2011 17:26:30 +0200
Noé Rubinstein <nrubinstein at proformatique.com> wrote:

> Hi,
> 
> I was looking for some way to decrease the flashing time with Flashrom
> for a 2MB SST SST25VF016B chip with a Dediprog SF100 programmer. After
> taking a look at the datasheet, stefanct suggested to try to change the
> write function for SST25VF016B to spi_aai_write, instead of
> spi_chip_write_1.
> 
> (I had tried changing it to spi_chip_write_256 some time ago.
> Unsurprisingly, the results were not so good)
> 
> I did some benchmark by writing random data on a chip already filled
> with random data. I attached the results. I've run the benchmark two
> times and got similar results on the two runs.
> 
> In short: 
> - with spi_aai_write, writing takes 56 minutes and seems to work reliably
> - with spi_chip_write_1, writing takes 143 minutes
> 
> I also ran the test with -VV but the log is so big I can't possibly
> send it to the mailing list. Here it is:
> http://neetwork.net/up/misc/bench_vv
> 
> I also attached the patch I applied to Flashrom's trunk.
> 

hello and thanks for the patch and testing!

great improvement, in relative terms at least ;)
regarding your patch... i just noticed that joshua has already posted a
patch for this and also some other sst chips:
http://patchwork.coreboot.org/patch/2065/

it would be great if you could look at the datasheets of all those
chips touched in the patch and verify what joshua did. to do this you
need to check if the chips support aai and if the opcode listed for
this is 0xad. if everything is correct please reply with an acked-by
like it is usually done (see other threads).

be aware though that applying this old patch most probably will either
fail (i.e. "patch" will bail out) or change the wrong lines. so an
updated patch would even be cooler, but is not necessary for the ack.

-- 
Kind regards/Mit freundlichen Grüßen, Stefan Tauner