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Date:   Mon, 13 Jun 2022 09:18:31 +0300
From:   Mika Westerberg <mika.westerberg@linux.intel.com>
To:     Oleksandr Ocheretnyi <oocheret@cisco.com>
Cc:     tudor.ambarus@microchip.com, miquel.raynal@bootlin.com,
        p.yadav@ti.com, michael@walle.cc, richard@nod.at, vigneshr@ti.com,
        broonie@kernel.org, linux-mtd@lists.infradead.org,
        linux-spi@vger.kernel.org, mauro.lima@eclypsium.com,
        lee.jones@linaro.org, linux-kernel@vger.kernel.org,
        xe-linux-external@cisco.com
Subject: Re: [PATCH] mtd: spi-nor: handle unsupported FSR opcodes properly
Message-ID: <YqbWt9f3of+7Z76e@lahna>
References: <YmZUCIE/ND82BlNh@lahna>
 <20220610191548.3626218-1-oocheret@cisco.com>
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Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
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Hi,

On Fri, Jun 10, 2022 at 12:15:48PM -0700, Oleksandr Ocheretnyi wrote:
> Commit 094d3b9 ("mtd: spi-nor: Add USE_FSR flag for n25q* entries")
> and following one 8f93826 ("mtd: spi-nor: micron-st: convert USE_FSR
> to a manufacturer flag") enables SPINOR_OP_RDFSR opcode handling ability,
> however some controller drivers still cannot handle it properly in
> the micron_st_nor_ready() call what breaks some mtd callbacks with
> next error logs:
> 
> mtdblock: erase of region [address1, size1] on "BIOS" failed
> mtdblock: erase of region [address2, size2] on "BIOS" failed
> 
> Just skip subsequent processing of the SPINOR_OP_RDFSR opcode's results
> because of -ENOTSUPP return value of the micron_st_nor_read_fsr()
> if there is no proper handling of that opcode as it's been before
> commit 094d3b9 ("mtd: spi-nor: Add USE_FSR flag for n25q* entries")
> 
> Signed-off-by: Oleksandr Ocheretnyi <oocheret@cisco.com>

I sent similar patch some time ago here:

https://lore.kernel.org/linux-mtd/20220506105158.43613-1-mika.westerberg@linux.intel.com/#t

but so far it has not been picked up by the maintainers. I'm fine if we
go with your patch instead, just one minor comment:

> ---
>  drivers/mtd/spi-nor/micron-st.c | 6 +++++-
>  drivers/spi/spi-intel.c         | 3 ++-
>  2 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/micron-st.c b/drivers/mtd/spi-nor/micron-st.c
> index a96f74e0f568..507e675d81e0 100644
> --- a/drivers/mtd/spi-nor/micron-st.c
> +++ b/drivers/mtd/spi-nor/micron-st.c
> @@ -399,8 +399,12 @@ static int micron_st_nor_ready(struct spi_nor *nor)
>  		return sr_ready;
>  
>  	ret = micron_st_nor_read_fsr(nor, nor->bouncebuf);
> -	if (ret)
> +	if (ret < 0) {
> +		/* Check if read FSR is supported. If not, skip it. */
> +		if (ret == -ENOTSUPP)
> +			return sr_ready;
>  		return ret;
> +	}
>  
>  	if (nor->bouncebuf[0] & (FSR_E_ERR | FSR_P_ERR)) {
>  		if (nor->bouncebuf[0] & FSR_E_ERR)
> diff --git a/drivers/spi/spi-intel.c b/drivers/spi/spi-intel.c
> index 50f42983b950..f0313a718d1b 100644
> --- a/drivers/spi/spi-intel.c
> +++ b/drivers/spi/spi-intel.c
> @@ -352,7 +352,8 @@ static int intel_spi_hw_cycle(struct intel_spi *ispi, u8 opcode, size_t len)
>  		val |= HSFSTS_CTL_FCYCLE_RDSR;
>  		break;
>  	default:
> -		return -EINVAL;
> +		dev_dbg(ispi->dev, "%#x not supported\n", opcode);
> +		return -ENOTSUPP;

I don't think this is necessary because we already return -EOPNOTSUPP in
intel_spi_exec_mem_op() so we can just check that one in
micron_st_nor_ready().

With that changed feel free to add my,

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>