diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index 37af27cbb..dc43eb83a 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -390,6 +390,22 @@ static int sendbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) return wrcount; } +static int acknak(struct i2c_adapter *i2c_adap, int is_ack) +{ + struct i2c_algo_bit_data *adap = i2c_adap->algo_data; + + /* assert: sda is high */ + if (is_ack) /* send ack */ + setsda(adap, 0); + udelay((adap->udelay + 1) / 2); + if (sclhi(adap) < 0) { /* timeout */ + dev_err(&i2c_adap->dev, "readbytes: ack/nak timeout\n"); + return -ETIMEDOUT; + } + scllo(adap); + return 0; +} + static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) { int inval; @@ -414,6 +430,10 @@ static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) (flags & I2C_M_NO_RD_ACK) ? "(no ack/nak)" : (count ? "A" : "NA")); + + inval = acknak(i2c_adap, count); + if (inval < 0) + return inval; } return rdcount; }