[PATCH] i2c: rk3x: fix bug that cause transfer fails in master receive mode

Sergei Shtylyov sergei.shtylyov at cogentembedded.com
Thu Aug 21 11:04:31 PDT 2014


Hello.

On 08/21/2014 09:50 PM, Addy Ke wrote:

> In rk3x SOC, the I2C controller can receive/transmit up to 32 bytes data
> in one transaction, so the size of data to be write/read to/from
> TXDATAx/RXDATAx must be less than or equal 32 bytes at a time.

> Test on pinky board, elan receive 158 bytes data.

> Signed-off-by: Addy Ke <addy.ke at rock-chips.com>
> ---
>   drivers/i2c/busses/i2c-rk3x.c | 3 +++
>   1 file changed, 3 insertions(+)

> diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
> index 69e1185..dc0aa64 100644
> --- a/drivers/i2c/busses/i2c-rk3x.c
> +++ b/drivers/i2c/busses/i2c-rk3x.c
> @@ -323,6 +323,9 @@ static void rk3x_i2c_handle_read(struct rk3x_i2c *i2c, unsigned int ipd)
>   	/* ack interrupt */
>   	i2c_writel(i2c, REG_INT_MBRF, REG_IPD);
>
> +	/* Can only handle a maximum of 32 bytes at a time */
> +	len = (len > 32) ? 32 : len;

    Why not min(len, 32)? Or even:

	if (len > 32)
		len = 32;

WBR, Sergei




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