2016-03-29 11:33 GMT+09:00 Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>:
> Commit 271707b1d817 ("mtd: nand: denali: max_banks calculation
> changed in revision 5.1") supported the new encoding of the "n_banks"
> bits of the "features" register, but there is an unfortunate case
> not covered by that commit.
>
> Panasonic (its System LSI Business Division is now Socionext) bought
> a couple of versions of this IP. The IP released for Panasonic
> around Feb. 2012 is revision 5 and uses the old encoding for n_banks
> (2 << n_banks). While the one released around Nov. 2012 is also
> revision 5, but it uses the new encoding (1 << n_banks).
>
> The revision register cannot distinguish these two incompatible
> hardware. I guess this IP series is not well-organized. I could not
> find any solution but giving max_banks from DT property.
>
> This commit works around the problem by allowing DT to set the
> max_banks forcibly. Of course, this DT property can be optional if
> the auto detection based on the hardware registers works well.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> Acked-by: Rob Herring <robh@xxxxxxxxxx>
Looks like we should take our time for discussion
to find out which is better, a new compatible string or a new DT property.
The discussion is happening in v1 thread.
http://patchwork.ozlabs.org/patch/601562/
Please hold back applying this patch.
--
Best Regards
Masahiro Yamada
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