Re: [PATCH v5 1/5] mtd: spi-nor: core: add manufacturer flags

Erez
2024-09-23T16:31:43Z

On Mon, 23 Sept 2024 at 18:19, Michael Walle <mwalle@kernel.org> wrote:
>
> Hi,
>
> > > > I would gladly remove the obsolete mx25l12805d.
> > > Why? I don't see any need for that.
> > Maybe because we do not want compatibility table?
>
> I don't get this? Anyway, we do not remove support for older
> flashes for no reason.

I did not insist, you asked.
Macronix stopped selling these chips 15 year ago.
How long do you want to support old chips?

>
> > No, reading the SFDP is great.
> > Except for OTP parameters/configuration.
> > As there is not way to find OTP parameters using JEDEC ID/SFDP
> > So as I understand there are only 2 ways to set the OTP parameters:
> > * Use a compatibility.
> > * Use dynamic OTP configuration, through DT, sysfs,
>
> * Use the in-kernel database to look up the parameters as it is done
> with any other flash device. If the id is reused, look for

All IDs in table are reused.
The change I suggest is to read SFDP to all Macronix chips.
As today, we skip the RDSFDP. "to avoid no-op".

> differences in the SFDP to figure out the correct flash device,

You can not do that unless you actually read the SFDP.

> then add some .fixups to manually add the OTP flags and
> parameters.

I am in favour.
As we can not use JEDEC ID or SFDP for OTP parameters.
How do you suggest manually OTP parameters?
Tudor Ambarus rejected my proposal.
I am open to implementing your suggestion.

I will split the two patches to avoid confusion.
So I will submit 2 patches:
* Always read Macronix chips SFDP, as Macronix replaced all old chips
in the Manufacture table.
* Support Macronix OTP.

Thanks for the feedback
Erez

>
> -michael