Re: [PATCH v5 1/3] mtd: spi-nor: add support for is25wp256

[Sagar Kadam]

Hello Vignesh,

Thanks for your review comments.

On Sun, Jun 16, 2019 at 6:14 PM Vignesh Raghavendra <vigneshr@xxxxxx> wrote:
>
> Hi,
>
> On 12-Jun-19 4:17 PM, Sagar Shrikant Kadam wrote:
> [...]
>
> > @@ -4129,7 +4137,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
> >       if (ret)
> >               return ret;
> >
> > -     if (nor->addr_width) {
> > +     if (nor->addr_width && JEDEC_MFR(info) != SNOR_MFR_ISSI) {
> >               /* already configured from SFDP */
>
> Hmm, why would you want to ignore addr_width that's read from SFDP table?

The SFDP table for ISSI device considered here, has addr_width set to
3 byte, and the flash considered
here is 32MB. With 3 byte address width we won't be able to access
flash memories higher address range.
Hence I have ignored the addr width from SFDP.  I have verified that
with 3 byte address width, the
flascp util fails while verifying the written data.  Please let me
know your views on this?

BR,
Sagar Kadam

> Regards
> Vignesh
>
>
> >       } else if (info->addr_width) {
> >               nor->addr_width = info->addr_width;
> > diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
> > index b3d360b..ff13297 100644
> > --- a/include/linux/mtd/spi-nor.h
> > +++ b/include/linux/mtd/spi-nor.h
> > @@ -19,6 +19,7 @@
> >  #define SNOR_MFR_ATMEL               CFI_MFR_ATMEL
> >  #define SNOR_MFR_GIGADEVICE  0xc8
> >  #define SNOR_MFR_INTEL               CFI_MFR_INTEL
> > +#define SNOR_MFR_ISSI                0x9d            /* ISSI */
> >  #define SNOR_MFR_ST          CFI_MFR_ST      /* ST Micro */
> >  #define SNOR_MFR_MICRON              CFI_MFR_MICRON  /* Micron */
> >  #define SNOR_MFR_MACRONIX    CFI_MFR_MACRONIX
> >