[PATCH] mtd: spi-nor: winbond: Make sure w25q{01,02}jv behave correctly

[Miquel Raynal]

Hello,

On 02/07/2025 at 11:23:13 +02, Miquel Raynal <miquel.raynal at bootlin.com> wrote:

> These chips are internally made of two/four dies with linear addressing
> capabilities to make it transparent to the user that two/four dies were
> used. There is one drawback however, the read status operation is racy
> as the status bit only gives the active die status and not the status of
> the other die. For commands affecting the two dies, it means if another
> command is sent too fast after the first die has returned a valid
> status (deviation can be up to 200us), the chip will get corrupted/in an
> unstable state.
>
> The solution adopted here is to iterate manually over all internal
> dies (which takes about 30us per die) until all are ready. This approach
> will always be faster than a blind delay which represents the maximum
> deviation, while also being totally safe.
>
> A flash-specific hook for the status register read had to be
> implemented. Testing with the flash_speed benchmark in Linux shown no
> difference with the existing performances (using the regular status read
> core function).
>
> As the presence of multiple dies is not filled in these chips SFDP
> tables (the table containing the crucial information is optional), we
> need to manually wire the hook.
>
> This change is adapted from Linux.
>
> Link: https://lore.kernel.org/all/20250110-winbond-6-12-rc1-nor-volatile-bit-v3-1-735363f8cc7d@bootlin.com/
> Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>

Same question for this one, no feedback for the past 2 months, I'm not
sure who's supposed to take these, Jagan and Vignesh you are marked M:
in maintainers, any chances this can get it?

Thanks a lot,
Miquèl