patches.renesas/0382-i2c-rcar-check-bus-free-before-first-message.patch

From 32cac77a5363a46de87b4fe680bfc7f554305253 Mon Sep 17 00:00:00 2001
From: Wolfram Sang <wsa+renesas@sang-engineering.com>
Date: Wed, 28 May 2014 09:44:40 +0200
Subject: i2c: rcar: check bus free before first message

We should always check if the bus is free, independently if it is a read
or write. It should be done before the first message, though. After
that, we ourselves keep the bus busy. Remove a 'ret' assignment which
only silenced a build warning.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
(cherry picked from commit 3f7de22eb28244fc79bc744d9f51d018da343962)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
 drivers/i2c/busses/i2c-rcar.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index f2cbb8a7d0ba..828b519146fc 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -294,15 +294,6 @@ static int rcar_i2c_recv(struct rcar_i2c_priv *priv)
 
 static int rcar_i2c_send(struct rcar_i2c_priv *priv)
 {
-	int ret;
-
-	/*
-	 * It should check bus status when send case
-	 */
-	ret = rcar_i2c_bus_barrier(priv);
-	if (ret < 0)
-		return ret;
-
 	rcar_i2c_set_addr(priv, 0);
 	rcar_i2c_status_clear(priv);
 	rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
@@ -508,7 +499,10 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 	spin_unlock_irqrestore(&priv->lock, flags);
 	/*-------------- spin unlock -----------------*/
 
-	ret = -EINVAL;
+	ret = rcar_i2c_bus_barrier(priv);
+	if (ret < 0)
+		goto out;
+
 	for (i = 0; i < num; i++) {
 		/* This HW can't send STOP after address phase */
 		if (msgs[i].len == 0) {
@@ -569,7 +563,7 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 
 		ret = i + 1; /* The number of transfer */
 	}
-
+out:
 	pm_runtime_put(dev);
 
 	if (ret < 0 && ret != -ENXIO)
-- 
2.1.2