Re: [PATCH v3 1/2] mtd: spi-nor: issi: is25wp256: Init flash based on SFDP

Guenter Roeck
2022-12-21T12:19:29Z

Hi Michael,

On Wed, Dec 21, 2022 at 09:22:04AM +0100, Michael Walle wrote:
> Hi,
>
> Am 2022-12-21 01:30, schrieb Guenter Roeck:
> > With this patch in place, qemu emulations with is25wp256 fail to
> > instantiate the flash. Specifically, this affects the qemu sifive_u
> > emulation. The resulting error message is:
> >
> > spi-nor spi0.0: BFPT parsing failed. Please consider using
> > SPI_NOR_SKIP_SFDP when declaring the flash
> > spi-nor: probe of spi0.0 failed with error -22
>
> qemu is to blame here. It doesn't fully emulate the flash. Esp. not
> the SFDP tables. See also [1]. Adding the .sfdp_read hook with the
> corresponding binary [2] should fix your issue.
>
> [1]
> https://lore.kernel.org/qemu-devel/7827c791b7f91f4eb216b33473dd6103@walle.cc/
> [2] https://lore.kernel.org/linux-mtd/CAHyZL-ch=mr0x_19e6P9G+Z4sW2iJXW9nTnXUNAhn+pTptN2ww@mail.gmail.com/
>

Great, that helped. I'll prepare and send a qemu patch.

Thanks,
Guenter