[U-Boot-Users] flash protection code in cfi_flash

Tolunay Orkun listmember at orkun.us
Thu Mar 16 18:57:36 CET 2006

David Ho wrote:
> Okay,
> I really didn't mean to rip out someone's code, I know it was there
> for a reason.  In any case, I like to understand which Intel flash is
> behaving badly.  The spec does not say unprotect unlocks all blocks.
First, I am not the author of this part of code. I can tell you the 
Intel StrataFlash 28F128J3 parts on my Cogent CSB272 board needs this 
code. Original author must have hit the same issue. This is a chip bug 
and probably documented on some Intel Errata and it may be applying to 
certain Revs of the chip. I do not have a list.
>>> If no one has any objection, I will remove the part of the code that
>>> relock each sector, for submission.
>> First, That behavior is required because some Intel flash parts
>> incorrectly unlock all sectors (not just current sector) so after
>> unlocking the current sector we must redo the locking of all others that
>> were supposed to remain locked. Again, the comment in that code reflects
>> and explains this.
> I am sorry, my interpretation of your comment led me to think you are
> suggesting all Intel flashes behave this way.  Really my original post
What is not clear about the word "some" in my description of the issue? 
I am obviously not claiming all Intel parts are this. Your 
interpretation is incorrect.

> came from a confusion of the comment.  A better comment may include
> what you just said above.
> Do you know which parts behave this way?  Has Intel confirmed this?
I do not need Intel's confirmation. It is a reality for me. Again, it is 
most likely documented in some Intel Errata (which might not be widely 
publicly circulated).

> Certainly not all flashes need to have this workaround, perhaps it is
> sensible to option it out?  Anyway, I have no problem with this code
> being there.  Since I have not seen the same behaviour you saw, and
> google did not turn up and evidence to support this, I was just
> curious if this has been solved since the code was first submitted.
I certainly do not have the capability to test each new rev of every 
Intel flash. Without a complete list you can only take the safe path...

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