[flashrom] [PATCH] Dediprog SF100 support

Stefan Reinauer stepan at coresystems.de
Tue Jan 19 13:14:45 CET 2010

On 1/19/10 1:08 PM, Carl-Daniel Hailfinger wrote:
> On 19.01.2010 12:43, Stefan Reinauer wrote:
>> On 1/19/10 12:36 PM, Carl-Daniel Hailfinger wrote:
>>> Hm. To be honest, reading is something I could not find in the logs.
>> I can provide a reading only log if that helps?
> Unfortunately that won't help. Reading uses USB bulk transfers without
> opcodes. This may sound strange, but the SF100 firmware seems to have a
> builtin mode where it issues the SPI READ opcode (or the FAST_READ
> opcode, no idea without a SPI sniffer log) if you send a special request
> without any opcode. As long as I have no idea about how to use this for
> partial reads, we can't use that mode.
Well, then you need a log for a partial read?

Frankly, it would still be around 60-100 times faster to always read the
whole chip and just through away what you don't need ;-)

> Good news: My patch works as designed. Read seems to work as well. Ack
> please?
> Bad news: The dediprog is dog slow. 
Not with the windows software. It looks like only your driver is slow,
not the dediprog ;-) But hey, it's a start.
> sloooooooow. Reading works, but for a 4 MByte chip it may take up to 35
> minutes AFAICS, maybe more. The file specified by -r will only be filled
> with contents after the read is complete.
Maybe it shouldn't be created before that, either, then?

> I see a speedup by a factor of 4 on the horizon, but I will implement
> that only after I get confirmation that read works correctly (would be
> pointless otherwise).
Requiring 10 minutes to read the chip is still kind of pointless, so I
don't know if it's worth the effort if the driver can't be generally fixed.


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