[U-Boot] CFI Driver Problem: flash not ready

Wolfgang Denk wd at denx.de
Mon Oct 20 00:10:26 CEST 2008


Dear Scott,

In message <48FBADA6.3090505 at psyent.com> you wrote:
> 
> > Why the heck does flash_is_busy() return 0 when the flashobviously is
> > still busy?
> 
> Does this use the toggle bit detection? I saw the same symptoms

Hm... how can I tell if it does?

The driver reports "AMD Standard command set", so it probably does.

> with Nios II. Basically, the memory controller was reading the
> 16-bit flash twice to obtain a full 32-bit word, then returning just
> the first 16-bits. So, I would never see the toggle bit changing.

Well, I see that no real 64 bit accesses are used, so I think we will
here see two 32 bit accesses  to  get  the  full  64  bit  data,  and
probably the same thin happens.

> Not sure if this is similar to your situation ... but it was a real
> pain-in-the-butt to finally understand what was happening in my
> situation.

And how did you fix it?

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The use of anthropomorphic terminology when  dealing  with  computing
systems is a symptom of professional immaturity.   -- Edsger Dijkstra


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