Question about SPI-NOR micron-st.c driver and OSPI devices.

[Pratyush Yadav]

Hi Mike,

On Mon, Jan 16 2023, Mike Williamson wrote:

> Hello,
>
> I am looking at the drivers/mtd/spi-not/micron-st.c file.
>
> I was wondering why the mt35xu512aba_fixups, and in general the patch below,
> were not also applied to the mt35xu02g device entry?  Best I can tell, the
> datasheets for the two parts (same family, different densities) look nearly
> identical and the
>
> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg2333941.html
>
> I ask because we are having some troubles with the mt35xu02g and I am
> wondering if we need these fixups to run reliably in octal mode.

When I wrote the patches for Octal DTR support on MT35 flash family, I
only had the mt35xu512aba flash on me. And it was a new feature so I did
not want to add it to a flash I could not test, and risk breaking it. I
figured if someone really wanted Octal DTR support on the 02G part, they
can populate the fixups and test it themselves.

So this is what I suggest you do as well. Add the fixups, test it out,
and if it works, upstream the patch. While you are at it, perhaps also
convert it to use the PARSE_SFDP flag. See db391efe765c ("mtd: spi-nor:
spansion: Remove NO_SFDP_FLAGS from s28hs512t info") or a30f53d8bc0f
("mtd: spi-nor: issi: is25wp256: Init flash based on SFDP") for example.

-- 
Regards,
Pratyush Yadav



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