diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-cadence.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c index 871cb58aaa06..7d7a14cdadfb 100644 --- a/drivers/i2c/busses/i2c-cadence.c +++ b/drivers/i2c/busses/i2c-cadence.c @@ -545,6 +545,20 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, * processed with a repeated start. */ if (num > 1) { + /* + * This controller does not give completion interrupt after a + * master receive message if HOLD bit is set (repeated start), + * resulting in SW timeout. Hence, if a receive message is + * followed by any other message, an error is returned + * indicating that this sequence is not supported. + */ + for (count = 0; count < num - 1; count++) { + if (msgs[count].flags & I2C_M_RD) { + dev_warn(adap->dev.parent, + "Can't do repeated start after a receive message\n"); + return -EOPNOTSUPP; + } + } id->bus_hold_flag = 1; reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET); reg |= CDNS_I2C_CR_HOLD; |