[PATCH v6, 5/8] mtd: m25p80: Let m25p80_read() fallback to spi transfer

[Florian Fainelli]

On 08/24/2016 03:04 PM, Kamal Dasu wrote:
> In m25p80_read() even though spi_flash_read() is supported
> by some drivers, under certain circumstances like unaligned
> buffer, address or address range limitations on certain SoCs
> let it fallback to core spi reads. Such drivers are expected
> to return -EAGAIN so that the m25p80_read() uses standard
> spi transfer.
> 
> Signed-off-by: Kamal Dasu <kdasu.kdev at gmail.com>

MTD folks, any comments on this?

> ---
>  drivers/mtd/devices/m25p80.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
> index 9cf7fcd..77c2d2c 100644
> --- a/drivers/mtd/devices/m25p80.c
> +++ b/drivers/mtd/devices/m25p80.c
> @@ -155,9 +155,16 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
>  		msg.data_nbits = m25p80_rx_nbits(nor);
>  
>  		ret = spi_flash_read(spi, &msg);
> -		if (ret < 0)
> +
> +		if (ret >= 0)
> +			return msg.retlen;
> +
> +		/*
> +		 * some spi master drivers might need to fallback to
> +		 * normal spi transfer
> +		 */
> +		if (ret != -EAGAIN)
>  			return ret;
> -		return msg.retlen;
>  	}
>  
>  	spi_message_init(&m);
> 

-- 
Florian