mtd: spi-nor: fatal issue during the mtd_erase() calls

[mika.westerberg at linux.intel.com]

Hi,

On Sat, Apr 23, 2022 at 10:32:28PM +0000, Oleksandr Ocheretnyi -X (oocheret - GLOBALLOGIC INC at Cisco) wrote:
>    Hello guys,
> 
>    recently I've faced the fatal issue "mtdblock: erase of region ... on
>    ... failed"
> 
>    working with MTD device (Micron n25q128a13) on recent kernels with
>    version
> 
>    5.15.x and newer.
> 
>    Commit 094d3b9 ("mtd: spi-nor: Add USE_FSR flag for n25q* entries")
>    adds
> 
>    SPINOR_OP_RDFSR opcode handling ability, however controller driver's
>    side
> 
>    (i.e. intel-spi) cannot handle it properly in the intel_spi_hw_cycle()
>    what causes
> 
>    a failures in the the spi_nor_fsr_ready() call what breaks some mtd
>    callbacks.
> 
>    Are there any plans to implement this SPINOR_OP_RDFSR opcode handling
> 
>    on the intel controller side? Is there acceptable way to provide
>    ENOTSUPP
> 
>    case response from controller driver side to spi-nor driver?

I think the Intel controller does support this internally but it does
not expose this to the software. I wonder if in this case we can, like
you suggest, return -ENOTSUPP and make micron_st_nor_ready() to handle
that case?

SPI-NOR folks, what you do think?