1 files changed, 15 insertions, 9 deletions

diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index b8feac5f2ef4..5795c8398c7c 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -331,21 +331,16 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
         INIT_COMPLETION(dev->cmd_complete);
         dev->cmd_err = 0;
 
-        /* Take I2C out of reset, configure it as master and set the
-         * start bit */
-        flag = DAVINCI_I2C_MDR_IRS | DAVINCI_I2C_MDR_MST | DAVINCI_I2C_MDR_STT;
+        /* Take I2C out of reset and configure it as master */
+        flag = DAVINCI_I2C_MDR_IRS | DAVINCI_I2C_MDR_MST;
 
         /* if the slave address is ten bit address, enable XA bit */
         if (msg->flags & I2C_M_TEN)
                 flag |= DAVINCI_I2C_MDR_XA;
         if (!(msg->flags & I2C_M_RD))
                 flag |= DAVINCI_I2C_MDR_TRX;
-        if (stop)
-                flag |= DAVINCI_I2C_MDR_STP;
-        if (msg->len == 0) {
+        if (msg->len == 0)
                 flag |= DAVINCI_I2C_MDR_RM;
-                flag &= ~DAVINCI_I2C_MDR_STP;
-        }
 
         /* Enable receive or transmit interrupts */
         w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG);
@@ -358,17 +353,28 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
         dev->terminate = 0;
 
         /*
+         * Write mode register first as needed for correct behaviour
+         * on OMAP-L138, but don't set STT yet to avoid a race with XRDY
+         * occuring before we have loaded DXR
+         */
+        davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
+
+        /*
          * First byte should be set here, not after interrupt,
          * because transmit-data-ready interrupt can come before
          * NACK-interrupt during sending of previous message and
          * ICDXR may have wrong data
+         * It also saves us one interrupt, slightly faster
          */
         if ((!(msg->flags & I2C_M_RD)) && dev->buf_len) {
                 davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, *dev->buf++);
                 dev->buf_len--;
         }
 
-        /* write the data into mode register; start transmitting */
+        /* Set STT to begin transmit now DXR is loaded */
+        flag |= DAVINCI_I2C_MDR_STT;
+        if (stop && msg->len != 0)
+                flag |= DAVINCI_I2C_MDR_STP;
         davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
 
         r = wait_for_completion_interruptible_timeout(&dev->cmd_complete,