RE: [PATCH RFC 0/4] Add set_iofv() callback

[Biju Das <biju.das.jz@bp.renesas.com>]

Hi Michael Walle,

> Subject: Re: [PATCH RFC 0/4] Add set_iofv() callback
> 
> Hi Biju,
> 
> >> > After that I will send a patch using IOFV {3,3,3,3} for both micron
> >> > and Adesto flash.
> >>
> >> Just to be clear, that will just touch the spi controller as a global
> >> default, right?
> >
> > Yes, it is in SoC specific bus controller
> > driver(driver/memory/renesas-rpc-if.c)
> >
> >> That shouldn't go through spi-nor. Otherwise I'd prefer to use fix
> >> (2) from my previous mail.
> >
> > Agreed. Fix(2) won't work as renesas-rpc-if probe which sets {3,3,3,3}
> > is called before flash detection.
> > and that will make flash detection to fail. So we cannot use fixup.
> > The only way (2) to work is to like patch[1].
> 
> Ohh I see. Makes sense. Can you ask your SoC engineers, why they choose
> the IO3 default to high? I'd guess because it's usually shared with HOLD#
> or RESET#. 

OK will ask and will update you once I get feedback.

>But that really begs the question why the Atmel flash isn't
> working with that setting. I suspect some problems during the turn around
> of the direction of IO3.
> You'd really have to probe with an oscilloscope though.

OK, but as per [1], 8.14, IO3 must be HiZ for Atmel flash.

[1] https://www.renesas.com/eu/en/document/dst/at25ql128a-datasheet?r=1608586

Cheers,
Biju


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