Merge tag 'isci-for-3.5' into misc

[firefly-linux-kernel-4.4.55.git] / drivers / i2c / busses / i2c-tegra.c

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index e978635e60f04189e6478ccb112a0df4a2596ed3..55e5ea62ccee3b69148c13ce337a1ff8531bc467 100644 (file)
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -516,6 +516,14 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
        if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
                return 0;
 
+       /*
+        * NACK interrupt is generated before the I2C controller generates the
+        * STOP condition on the bus. So wait for 2 clock periods before resetting
+        * the controller so that STOP condition has been delivered properly.
+        */
+       if (i2c_dev->msg_err == I2C_ERR_NO_ACK)
+               udelay(DIV_ROUND_UP(2 * 1000000, i2c_dev->bus_clk_rate));
+
        tegra_i2c_init(i2c_dev);
        if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
                if (msg->flags & I2C_M_IGNORE_NAK)