Re: [PATCH] sf: Querying write-protect status before operating the

[Michael Walle <michael@walle.cc>]

> On Fri, Nov 5, 2021 at 10:47 PM <Tudor.Ambarus@microchip.com> wrote:
> >
> > Hi,
> >
> > On 6/22/21 8:21 AM, chao zeng wrote:
> > > From: Chao Zeng <chao.zeng@siemens.com>
> > >
> > > When operating the write-protection flash,spi_flash_std_write() and
> > > spi_flash_std_erase() would return wrong result.The flash is protected,
> > > but write or erase the flash would show "OK".
> > >
> > > Check the flash write protection state if the write-protection has enbale
> > > before operating the flash.
> > >
> > > Signed-off-by: Chao Zeng <chao.zeng@siemens.com>
> > > ---
> > >
> > >  drivers/mtd/spi/sf_probe.c | 10 ++++++++++
> > >  1 file changed, 10 insertions(+)
> > >
> > > diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c
> > > index 3befbe91ca..f06e6b88bd 100644
> > > --- a/drivers/mtd/spi/sf_probe.c
> > > +++ b/drivers/mtd/spi/sf_probe.c
> > > @@ -109,6 +109,11 @@ static int spi_flash_std_write(struct udevice *dev, u32 offset, size_t len,
> > >       struct mtd_info *mtd = &flash->mtd;
> > >       size_t retlen;
> > >
> > > +     if (flash->flash_is_locked && flash->flash_is_locked(flash, offset, len)) {
> > > +             debug("SF: Flash is locked\n");
> > > +             return -ENOPROTOOPT;
> >
> > Keep a debug message, but return 0 please. Writes or erases on protected areas
> > are ignored by the flash, we should reflect that in the code.

Mh, will this then make the whole write fail? We do rely on the fact,
that we can update the whole flash image, but the first sectors will
be 'skipped' because the first are write-protected. I guess this patch
will then break this.

Shouldn't this then be on a per sector basis?

-michael