i2c: rcar: clarify PM handling with more comments

PM handling is correct but might be a bit subtle. Add some comments for
clarification.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 66b84bf51bbfd06350d9187c5c17b6632af417b7..214bf2835d1f95ff176cb0ded24654b20b821944 100644 (file)
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -753,6 +753,7 @@ static int rcar_reg_slave(struct i2c_client *slave)
        if (slave->flags & I2C_CLIENT_TEN)
                return -EAFNOSUPPORT;
 
+       /* Keep device active for slave address detection logic */
        pm_runtime_get_sync(rcar_i2c_priv_to_dev(priv));
 
        priv->slave = slave;
@@ -856,13 +857,14 @@ static int rcar_i2c_probe(struct platform_device *pdev)
        priv->dma_direction = DMA_NONE;
        priv->dma_rx = priv->dma_tx = ERR_PTR(-EPROBE_DEFER);
 
+       /* Activate device for clock calculation */
        pm_runtime_enable(dev);
        pm_runtime_get_sync(dev);
        ret = rcar_i2c_clock_calculate(priv, &i2c_t);
        if (ret < 0)
                goto out_pm_put;
 
-       /* Don't suspend when multi-master to keep arbitration working */
+       /* Stay always active when multi-master to keep arbitration working */
        if (of_property_read_bool(dev->of_node, "multi-master"))
                priv->flags |= ID_P_PM_BLOCKED;
        else