Re: [PATCH v2 2/2] i2c: qup: support SMBus block read

[Christ, Austin]

On 5/20/2016 2:31 AM, Sricharan wrote:
Hi,

<snip..>
@@ -1128,6 +1173,22 @@ static int qup_i2c_read_one_v2(struct
qup_i2c_dev *qup, struct i2c_msg *msg)
                        goto err;

                qup->blk.pos++;
+
+               /* Handle SMBus block read length */
+               if (qup_i2c_check_msg_len(msg) && (msg->len == 1)) {
+                       if (msg->buf[0] > I2C_SMBUS_BLOCK_MAX) {
+                               ret = -EPROTO;
+                               goto err;
+                       }
+                       msg->len += msg->buf[0];
+                       qup->pos = 0;
+                       qup_i2c_set_read_mode_v2(qup, msg->len);
+                       qup_i2c_issue_xfer_v2(qup, msg);
+                       ret = qup_i2c_wait_for_complete(qup, msg);
+                       if (ret)
+                               goto err;
                Is the issue_xfer_v2 needed inside this here ?
No, qup_i2c_issue_xfer_v2 is needed so that we read rest of the data
that is indicated by the length we read earlier.
So qup_i2c_issue_xfer_v2 writes the tags and there is one already in the loop 
above this
  check. So if you just do qup_i2c_set_read_mode_v2 and qup_i2c_set_blk_data 
inside this
  check, will not be enough ?

Regards,
  Sricharan

In testing, removing the call to qup_i2c_issue_xfer_v2() within the 
conditional statement for SMBus length causes failures. That transfer 
request is needed to read that block of data.

Thanks,
Austin