[PATCH] mtd: spi-nor: handle unsupported FSR opcodes properly

[Mika Westerberg]

On Wed, Jun 15, 2022 at 08:10:13PM +0200, Michael Walle wrote:
> Am 15. Juni 2022 11:49:22 OEZ schrieb Mika Westerberg <mika.westerberg at linux.intel.com>:
> >Hi,
> >
> >On Tue, Jun 14, 2022 at 05:56:54PM +0000, Oleksandr Ocheretnyi -X (oocheret - GLOBALLOGIC INC at Cisco) wrote:
> >>    Hello Mika,
> >> 
> >>    in my case (I work with memory chip n25q128a13 for recent kernels) I'm
> >>    getting return value -ENOTSUPP from spi_mem_exec_op() call in the
> >>    micron_st_nor_read_fsr() method
> >>    [[1]https://elixir.bootlin.com/linux/v5.19-rc2/source/drivers/spi/spi-m
> >>    em.c#L326]. So I decided to provide the same errorcode to
> >>    intel_spi_hw_cycle() method because older kernel versions throw the
> >>    error there. It is fine to use -EOPNOTSUPP return value instead.
> >> 
> >>    I suspect we need to cover both cases to check -ENOTSUPP as well as
> >>    -EOPNOTSUPP to let the driver work properly.
> >> 
> >>    if (ret == -ENOTSUPP || ret == -EOPNOTSUPP)
> >
> >I think we should follow the same in the Intel driver and return
> >-ENOTSUPP too.
> 
> AFAIK ENOTSUPP is for nfs and shouldn't be used.

Yes, but that's what the SPI-NOR core is using so I think we want to be
consistent with it.