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Date:   Thu, 10 Oct 2019 09:33:08 +0200
From:   Boris Brezillon <boris.brezillon@collabora.com>
To:     <Tudor.Ambarus@microchip.com>
Cc:     <vigneshr@ti.com>, <marek.vasut@gmail.com>,
        <linux-mtd@lists.infradead.org>, <geert+renesas@glider.be>,
        <jonas@norrbonn.se>, linux-aspeed@lists.ozlabs.org,
        andrew@aj.id.au, richard@nod.at, linux-kernel@vger.kernel.org,
        vz@mleia.com, linux-mediatek@lists.infradead.org, joel@jms.id.au,
        miquel.raynal@bootlin.com, matthias.bgg@gmail.com,
        computersforpeace@gmail.com, dwmw2@infradead.org,
        linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 09/22] mtd: spi-nor: Fix retlen handling in
 sst_write()
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        <20190924074533.6618-10-tudor.ambarus@microchip.com>
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On Tue, 24 Sep 2019 07:46:21 +0000
<Tudor.Ambarus@microchip.com> wrote:

> From: Tudor Ambarus <tudor.ambarus@microchip.com>
> 
> In case the write of the first byte failed, retlen was incorrectly
> incremented to *retlen += actual; on the exit path. retlen should be
> incremented when actual data was written to the flash.
> 
> Rename 'sst_write_err' label to 'out' as it is no longer generic for
> all the write errors in the sst_write() method, and may introduce
> confusion.

Renaming the label is indeed a good thing, but should be done in a
separate patch.

> 
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> ---
>  drivers/mtd/spi-nor/spi-nor.c | 22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 0aee068a5835..be5dee622d51 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -2665,12 +2665,12 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
>  		/* write one byte. */
>  		ret = spi_nor_write_data(nor, to, 1, buf);
>  		if (ret < 0)
> -			goto sst_write_err;
> +			goto unlock_and_unprep;
>  		WARN(ret != 1, "While writing 1 byte written %i bytes\n",
>  		     (int)ret);
>  		ret = spi_nor_wait_till_ready(nor);
>  		if (ret)
> -			goto sst_write_err;
> +			goto unlock_and_unprep;
>  	}
>  	to += actual;

Not sure we need this new label, we can just have:

	actual = 0;
	/* Start write from odd address. */
	if (to % 2) {
		nor->program_opcode = SPINOR_OP_BP;

		/* write one byte. */
		ret = spi_nor_write_data(nor, to, 1, buf);
		if (ret < 0)
			goto out;
		WARN(ret != 1, "While writing 1 byte written %i
		bytes\n", (int)ret);
		ret = spi_nor_wait_till_ready(nor);
		if (ret)
			goto out;

		to++;
		actual++;
	}

>  
> @@ -2681,12 +2681,12 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
>  		/* write two bytes. */
>  		ret = spi_nor_write_data(nor, to, 2, buf + actual);
>  		if (ret < 0)
> -			goto sst_write_err;
> +			goto out;
>  		WARN(ret != 2, "While writing 2 bytes written %i bytes\n",
>  		     (int)ret);
>  		ret = spi_nor_wait_till_ready(nor);
>  		if (ret)
> -			goto sst_write_err;
> +			goto out;
>  		to += 2;
>  		nor->sst_write_second = true;
>  	}
> @@ -2694,35 +2694,35 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
>  
>  	ret = spi_nor_write_disable(nor);
>  	if (ret)
> -		goto sst_write_err;
> +		goto out;
>  
>  	ret = spi_nor_wait_till_ready(nor);
>  	if (ret)
> -		goto sst_write_err;
> +		goto out;
>  
>  	/* Write out trailing byte if it exists. */
>  	if (actual != len) {
>  		ret = spi_nor_write_enable(nor);
>  		if (ret)
> -			goto sst_write_err;
> +			goto out;
>  
>  		nor->program_opcode = SPINOR_OP_BP;
>  		ret = spi_nor_write_data(nor, to, 1, buf + actual);
>  		if (ret < 0)
> -			goto sst_write_err;
> +			goto out;
>  		WARN(ret != 1, "While writing 1 byte written %i bytes\n",
>  		     (int)ret);
>  		ret = spi_nor_wait_till_ready(nor);
>  		if (ret)
> -			goto sst_write_err;
> +			goto out;
>  
>  		ret = spi_nor_write_disable(nor);
>  		if (ret)
> -			goto sst_write_err;
> +			goto out;
>  
>  		actual += 1;
>  	}
> -sst_write_err:
> +out:
>  	*retlen += actual;
>  unlock_and_unprep:
>  	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_WRITE);