[U-Boot-Users] CFI flash polling for AMD/SPANSION?

[Kumar Gala]

On Nov 27, 2007, at 12:41 PM, Stefan Roese wrote:

> Hi Kumar,
>
> On Tuesday 27 November 2007, Kumar Gala wrote:
>> So we have a patch to CFI flash to use DQ7/#data polling instead of
>> DQ6/toggle.  There seems to have been some discussion from time to
>> time regard this and several people have reported empirical evidence
>> about how DQ7 appears to work better for them on some systems.
>
> I have to admit, that I don't remember those discussions. Could you  
> please
> refresh my memory? And why exactly are you implementing this change?  
> What
> problem does it fix?

http://search.gmane.org/?query=DQ7&group=gmane.comp.boot-loaders.u-boot

I'm told that higher frequencies we have issues using the toggle  
method on 85xx/86xx parts from freescale.  But use DQ7 at those freq  
seems to work reliable for the flash parts we have on some of the  
boards.

>> I was hoping to understand what the issues are with getting such a
>> change accepted.
>
> If your patch fixes a problem, then chances are quite good. :)
>
> BTW: What does Linux MTD do? DQ7/data or DQ6/toggle? (I'm just too  
> lazy to
> check myself :))

It looks like it just uses DQ6/toggle if I'm reading the code correctly.

- k