[PATCH 2/2] mtd: spi-nor: disable 16-bit-sr for macronix

[Michael Walle]

Am 2021-12-31 10:10, schrieb Nick:
> I looked now through all datasheets I found and the sizes of the
> status register. However, I did not find any datasheet for the
> "mx66l1g55g".
> However, I am not sure if I maybe miss something to see if
> "SNOR_F_HAS_16BIT_SR" is supported. I only looked at the status
> register size.

How did you check that?

random example:
> mx66u51235f: 8bit
> https://www.macronix.com/Lists/Datasheet/Attachments/7674/MX66U51235F,%201.8V,%20512Mb,%20v1.1.pdf
> (slide 34)

Figure 23:
WRSR takes both status register and configuration register.

That being said. I'd prefer to have a sane default for that
flag - which is to _not_ set it by default. For now, we can
just remove the flag from spi_nor_init_default_params() and
move it into the manufacturer default init. Then we can
go through the flashes and remove the flag there.

This is mainly because it seems to be a legacy feature. To
quote the datasheet of the Winbond W25Q32FW [1]:

| The W25Q32FW is also backward compatible to Winbond’s previous
| generations of serial flash memories, in which the Status
| Register-1&2 can be written using a single “Write Status
| Register-1 (01h)” command.

-michael

[1] 
https://www.winbond.com/resource-files/w25q32fw%20revj%2004242018%20sfdp.pdf