1 files changed, 32 insertions, 20 deletions

diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index 8a5f5825bb72..7f0a0a62cf60 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -357,13 +357,29 @@ 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;
         int rdcount=0;          /* counts bytes read */
-        struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
         unsigned char *temp = msg->buf;
         int count = msg->len;
+        const unsigned flags = msg->flags;
 
         while (count > 0) {
                 inval = i2c_inb(i2c_adap);
@@ -377,28 +393,12 @@ static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
                 temp++;
                 count--;
 
-                if (msg->flags & I2C_M_NO_RD_ACK) {
-                        bit_dbg(2, &i2c_adap->dev, "i2c_inb: 0x%02x\n",
-                                inval);
-                        continue;
-                }
-
-                /* assert: sda is high */
-                if (count)              /* send ack */
-                        setsda(adap, 0);
-                udelay((adap->udelay + 1) / 2);
-                bit_dbg(2, &i2c_adap->dev, "i2c_inb: 0x%02x %s\n", inval,
-                        count ? "A" : "NA");
-                if (sclhi(adap)<0) {    /* timeout */
-                        dev_err(&i2c_adap->dev, "readbytes: timeout at ack\n");
-                        return -ETIMEDOUT;
-                };
-                scllo(adap);
-
                 /* Some SMBus transactions require that we receive the
                    transaction length as the first read byte. */
-                if (rdcount == 1 && (msg->flags & I2C_M_RECV_LEN)) {
+                if (rdcount == 1 && (flags & I2C_M_RECV_LEN)) {
                         if (inval <= 0 || inval > I2C_SMBUS_BLOCK_MAX) {
+                                if (!(flags & I2C_M_NO_RD_ACK))
+                                        acknak(i2c_adap, 0);
                                 dev_err(&i2c_adap->dev, "readbytes: invalid "
                                         "block length (%d)\n", inval);
                                 return -EREMOTEIO;
@@ -409,6 +409,18 @@ static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
                         count += inval;
                         msg->len += inval;
                 }
+
+                bit_dbg(2, &i2c_adap->dev, "readbytes: 0x%02x %s\n",
+                        inval,
+                        (flags & I2C_M_NO_RD_ACK)
+                                ? "(no ack/nak)"
+                                : (count ? "A" : "NA"));
+
+                if (!(flags & I2C_M_NO_RD_ACK)) {
+                        inval = acknak(i2c_adap, count);
+                        if (inval < 0)
+                                return inval;
+                }
         }
         return rdcount;
 }