[PATCH] mtd: spi-nor: fix the wrong dummy value

[Gerhard Sittig]

On Wed, 2014-04-16 at 16:18 +0800, Huang Shijie wrote:
> 
> The dummy cycles is actually 8 for SPI fast/dual/quad read.
> 
> This patch fixes the wrong dummy value for both the spi-nor.c and m25p80.c.
> 
> Signed-off-by: Huang Shijie <b32955 at freescale.com>
> ---
>  drivers/mtd/devices/m25p80.c  |    3 +++
>  drivers/mtd/spi-nor/spi-nor.c |    2 +-
>  2 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
> index 1557d8f..112ca8b 100644
> --- a/drivers/mtd/devices/m25p80.c
> +++ b/drivers/mtd/devices/m25p80.c
> @@ -131,6 +131,9 @@ static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
>  	int dummy = nor->read_dummy;
>  	int ret;
>  
> +	/* convert the dummy cycles to the number of byte */
> +	dummy >>= 3;
> +

"dummy /= 8" to match the comment / commit message, and for
better mental association with a byte's width and the below
return value?

is the number of bits guaranteed to always be a multiple of 8
bits?  I guess it is for m25p80, but thought I'd ask (have seen
"odd" numbers like 6 bits in quad spi implementations -- those
are impossible to run with "traditional" SPI controllers)

>  	/* Wait till previous write/erase is done. */
>  	ret = nor->wait_till_ready(nor);
>  	if (ret)
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index cd4b277..b88cc7e 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -77,7 +77,7 @@ static inline int spi_nor_read_dummy_cycles(struct spi_nor *nor)
>  	case SPI_NOR_FAST:
>  	case SPI_NOR_DUAL:
>  	case SPI_NOR_QUAD:
> -		return 1;
> +		return 8;
>  	case SPI_NOR_NORMAL:
>  		return 0;
>  	}


virtually yours
Gerhard Sittig
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