[PATCH] i2c-cpm: Fix to takeback i2c bus master-ship after a collision

[sachin surendran]

Hi Kumar,
             I have resent the updated patch.

Regards
Sachin

On Mon, Nov 26, 2012 at 2:21 AM, Kumar Gala <galak at kernel.crashing.org> wrote:
>
> 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 <sachin.surendran at alliedtelesis.co.nz>
>> ---
>>  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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>