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

[Jagan Teki]

On Tue, Sep 9, 2025 at 3:43 PM Miquel Raynal <miquel.raynal at bootlin.com> wrote:
>
> 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?

Unfortunately, I was off quite some-time. Need little bit of time.
Vighnesh is off for years. In the meantime, Michael will help in
review but need help on testing.

Thanks,
Jagan.