[PATCH 03/10] mtd: spi-nor: add SPI NOR manufacturer IDs

Brian Norris computersforpeace at gmail.com
Mon Sep 28 16:13:46 PDT 2015


On Mon, Sep 28, 2015 at 02:42:24PM +0530, Jagan Teki wrote:
> On 28 September 2015 at 06:16, Brian Norris <computersforpeace at gmail.com> wrote:
> > The whole point of this patch is that some mfrs use different IDs for
> > different classes of flash, so we shouldn't force our programming
> > patterns into looking like CFI (i.e., parallel NOR [1]) when we're
> > talking about serial NOR.
> >
> > If you'd rather, I can just copy the values into this header (e.g.,
> > 0x01, 0x89, etc.) and completely remove all references to CFI.
> 
> Understand your intention,

Do you? It really doesn't seem like it.

> but if what are the mfrs id's same then
> it's better to use already defined CFI notation because we may get
> into impression that the mfrs uses same id for CFI and SPINOR

CFI is really unrelated, for the most part. Parallel and serial NOR
evolved quite differently. Why would we want that impression, again?

Really, is it that hard to understand why we'd want two separate MFR ID
lists -- one for CFI and one for SPI NOR -- when it's quite clear that
those lists are NOT the same? Why should you needlessly ask programmers
to jump between using CFI_MFR_* and SNOR_MFR_* in the same framework?
What if someone starts trying to use CFI_MFR_WINBOND (which is NOT
correct for SPI NOR)? I'm trying *clarify* the ID namespace here, not
convolute it...

> (as cfi
> and spinor are NOR complaint flash memories) - IMHO.

That doesn't make any sense. "NOR" is not anything to be "compliant" to;
it's a type of flash technology (i.e., electrical design).

Brian



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