Re: [PATCH v4 05/20] dt-bindings: memory: factorise LPDDR props into SDRAM props

[Clement LE GOFFIC]

Hi Julius,

On 7/25/25 00:33, Julius Werner wrote:
> > > I don't think this will identify a part unambiguously, I would expect
> > > the DDR revision ID to be specific to the part number. (In fact, we're
> > > also not sure whether manufacturer+revision identifies LPDDR parts
> > > unambiguously for every vendor, we just didn't have anything more to
> > > work with there.) I would suggest to use either `ddrX-YYYY,AAA...,ZZ`
> > > or `ddrX-YYYY,ZZ,AAA...` (where AAA... is the part number string from
> > > SPD 329-348 without the trailing spaces). The first version looks a
> > > bit more natural but it might get confusing on the off chance that
> > > someone uses a comma in a part number string.
> >
> > The first one seems better indeed.
> > If the manufacturer put a comma in the part number we should handle it
> > at a software level to me and if it is a devicetree error it is up to
> > the devicetree writer to fix it.
> > What do you think ?

I meant exactly what you are stating below :-)

> Not sure what you mean by "handle it at a software level"? Using comma
> characters in the part number is not illegal according to the SPD
> spec, as far as I can tell.
>
> That said, it is still possible to disambiguate this as long as the
> revision number is always there, you just have to look for the last
> comma from the end (so e.g. the string `ddr4-1234,some,part,567,89`
> could be unambiguously parsed as manufacturer ID 0x1234, part number
> `some,part,567` and revision ID 0x89, the parsing code just needs to
> be a bit careful). So maybe this is not actually a problem.

Best regards,
Clément