[PATCH] mtd: cfi_cmdset_0001 - fixup for PC28F512P33TFA

[Joakim Tjernlund]

Christoph Fritz <chf.fritz at googlemail.com> wrote on 2014/04/01 00:04:20:
> 
> On Mon, 2014-03-31 at 22:31 +0200, Joakim Tjernlund wrote:
> > No way, disabling erase suspend will cause severe latencies for 
read/write 
> > ops.
> 
> Here on a mx35 it's not really severe.

There has been complaints in the past with no erase suspend.
You get delays considering that an erase takes c.a 1 sek so
once you get into a state where GC is erasing lots of blocks and other
progs wants read/write you will notice.

> 
> > The document mentions other ways to get around this problem, I suggest 
you 
> > explore
> > these first.
> 
> Already tried the “0xFF” dummy write cycle suggestion, should have
> mentioned that.

OK, but one more workaround(the udelay part) is required, right?

Also, the doc. is written in 2011 and only mentions some revisions of P3x 
has this
problem. Are these problems still present in current flash parts?

> 
> > Minus degrees is not a common environment either so perhaps any fix 
should 
> > be selectable?
> 
> The NOR is specified for down to -40°C.

That is a lot I guess but not everyone runs the equipment at these 
temperatures.