Re: [PATCH v4 3/3] mtd: spi-nor: Add support for IS25LX256 operating in 1S-8S-8S octal read mode

[Tudor Ambarus]

On 26.12.2022 10:04, Tudor Ambarus wrote:
> Hi, Nathan,
>
> The series is starting to look good, but I'll need another version,
> please.
>
> On 02.12.2022 15:55, Nathan Barrett-Morrison wrote:
> > This adds the IS25LX256 chip into the ISSI flash_info parts table
>
> Describe your changes in imperative mood, e.g. "Add support for
> S25LX256" instead of "This adds ..."
>
> It may worth to re-read
> https://www.kernel.org/doc/html/latest/process/submitting-patches.html
> once in a while.
>
> > Signed-off-by: Nathan Barrett-Morrison <nathan.morrison@xxxxxxxxxxx>
> > ---
> >   drivers/mtd/spi-nor/issi.c | 32 ++++++++++++++++++++++++++++++++
> >   1 file changed, 32 insertions(+)
> >
> > diff --git a/drivers/mtd/spi-nor/issi.c b/drivers/mtd/spi-nor/issi.c
> > index 89a66a19d754..362bc3603d8f 100644
> > --- a/drivers/mtd/spi-nor/issi.c
> > +++ b/drivers/mtd/spi-nor/issi.c
> > @@ -29,6 +29,35 @@ static const struct spi_nor_fixups is25lp256_fixups 
> > = {
> >       .post_bfpt = is25lp256_post_bfpt_fixups,
> >   };
> > +static int
> > +is25lx256_post_bfpt_fixups(struct spi_nor *nor,
> > +               const struct sfdp_parameter_header *bfpt_header,
> > +               const struct sfdp_bfpt *bfpt)
> > +{
> > +    /*
> > +     * IS25LX256 supports both 1S-1S-8S and 1S-8S-8S.
> > +     * However, the BFPT does not contain any information denoting this
> > +     * functionality, so the proper fast read opcodes are never setup.
> > +     * We're correcting this issue via the fixup below.  Page program
> > +     * commands are detected and setup properly via the 4BAIT lookup.
> > +     */

Why don't you set the READ support when parsing the 4bait table? We need
to see the SFDP dump to determine how we treat this. I'm not sure a
post_bfpt hook is the right thing to do for this flash.

Thanks,
ta