linux-kernel - Re: [PATCH v4 3/3] mtd: spi-nor: Rework hwcaps selection for the spi-mem case

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Message-ID: <ca327faa-d716-9ef3-f368-e496a40c6e2e@microchip.com>
Date:   Mon, 5 Aug 2019 17:45:53 +0000
From:   <Tudor.Ambarus@...rochip.com>
To:     <vigneshr@...com>, <miquel.raynal@...tlin.com>, <richard@....at>
CC:     <marek.vasut@...il.com>, <bbrezillon@...nel.org>,
        <linux-kernel@...r.kernel.org>, <linux-mtd@...ts.infradead.org>,
        <tmaimon77@...il.com>
Subject: Re: [PATCH v4 3/3] mtd: spi-nor: Rework hwcaps selection for the
 spi-mem case



On 08/01/2019 07:22 PM, Vignesh Raghavendra wrote:
> +static int spi_nor_spimem_check_op(struct spi_nor *nor,
> +				   struct spi_mem_op *op)
> +{
> +	/*
> +	 * First test with 4 address bytes. The opcode itself might
> +	 * be a 3B addressing opcode but we don't care, because
> +	 * SPI controller implementation should not check the opcode,
> +	 * but just the sequence.
> +	 */
> +	op->addr.nbytes = 4;
> +	if (!spi_mem_supports_op(nor->spimem, op)) {
> +		/* If flash size <16MB, 3 address bytes are sufficient */
> +		if (nor->mtd.size <= SZ_16M) {
> +			op->addr.nbytes = 3;
> +			if (!spi_mem_supports_op(nor->spimem, op))
> +				return -ENOTSUPP;
> +		}

this returns success when:
	op->addr.nbytes == 4 && !spi_mem_supports_op(nor->spimem, op) &&
	!(nor->mtd.size <= SZ_16M))

which is wrong.

The patch looks good otherwise!

> +	}
> +
> +	return 0;
> +}