On Oct 30, 2012, at 10:00 PM, sachin surendran wrote:
> In case of collision on i2c bus the controller which lost bus mastership
> stays as a slave
> for all subsequent transfers. This results in the i2c controller never
> writing to the bus
> for future transactions, resulting in i2c transfer timeouts.
> This fix checks for a collision on last I2C transaction and sets the
> I2COM_MASTER
> bit for the new transaction.
>
> Signed-off-by: Sachin Surendran <[email protected]>
> ---
> drivers/i2c/busses/i2c-cpm.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
patch doesn't apply, please resend properly.
- k
>
> diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c
> index c1e1096..bb94c6d 100644
> --- a/drivers/i2c/busses/i2c-cpm.c
> +++ b/drivers/i2c/busses/i2c-cpm.c
> @@ -338,6 +338,14 @@ static int cpm_i2c_xfer(struct i2c_adapter *adap, struct
> i2c_msg *msgs, int num)
> tptr = 0;
> rptr = 0;
>
> + /*
> + * If there was a collision in the last i2c transaction,
> + * Set I2COM_MASTER as it was cleared during collision.
> + */
> + if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
> + out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);
> + }
> +
> while (tptr < num) {
> pmsg = &msgs[tptr];
> dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr);
>
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