[PATCH v4 1/6] mtd: spi-nor: Add manufacturer read id function

[Michael Walle]

Hi,

>> I see this flash supports 1-1-1, 8-8-8, and 8d-8d-8d, there are no 
>> mixed
>> modes supported, thus a 8d-8d-8s mode seems just like a hardware bug 
>> to
>> me. So my proposal is to leave the core away and to handle the read id
>> hack just in the macronix driver.
> 
> +1

I've looked at the xspi spec. There is no RDID specified. So I'd argue,
the only pseudo standard is that RDID was only ever used with 1s1s1s. 
But
we added spi_nor_read_id() with parameters suited for the "unusual" 
8d8d8d
case with additional address and dummy cycles. Just for checking whether 
the
octal-dtr switch was successful. Therefore, we've already added 
parameters to
spi_nor_read_id() which are not standard. Then we can just add one more. 
It's
just how macronix is doing it. Again there is no standard.
If we'd only put standard (or for the 9F pseudo standard) things in the 
core,
then spi_nor_read_id() would need to check whether the flash is in 
1s1s1s
mode. And no I wouldn't prefer that ;)

-michael