Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c fixes from Wolfram Sang:

 - I2C core bugfix regarding bus recovery

 - driver bugfix for the tegra driver

 - typo correction

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: recovery: if possible send STOP with recovery pulses
  i2c: tegra: Fix NACK error handling
  i2c: stu300: use non-archaic spelling of failes

3 files changed, 19 insertions, 11 deletions

diff --git a/drivers/i2c/busses/i2c-stu300.c b/drivers/i2c/busses/i2c-stu300.c
index e866c481bfc3..fce52bdab2b7 100644
--- a/drivers/i2c/busses/i2c-stu300.c
+++ b/drivers/i2c/busses/i2c-stu300.c
@@ -127,7 +127,7 @@ enum stu300_error {
 
 /*
  * The number of address send athemps tried before giving up.
- * If the first one failes it seems like 5 to 8 attempts are required.
+ * If the first one fails it seems like 5 to 8 attempts are required.
  */
 #define NUM_ADDR_RESEND_ATTEMPTS 12
 
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 5fccd1f1bca8..797def5319f1 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -545,6 +545,14 @@ static int tegra_i2c_disable_packet_mode(struct tegra_i2c_dev *i2c_dev)
 {
 	u32 cnfg;
 
+	/*
+	 * NACK interrupt is generated before the I2C controller generates
+	 * the STOP condition on the bus. So wait for 2 clock periods
+	 * before disabling the controller so that the STOP condition has
+	 * been delivered properly.
+	 */
+	udelay(DIV_ROUND_UP(2 * 1000000, i2c_dev->bus_clk_rate));
+
 	cnfg = i2c_readl(i2c_dev, I2C_CNFG);
 	if (cnfg & I2C_CNFG_PACKET_MODE_EN)
 		i2c_writel(i2c_dev, cnfg & ~I2C_CNFG_PACKET_MODE_EN, I2C_CNFG);
@@ -706,15 +714,6 @@ 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 the 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)
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 31d16ada6e7d..301285c54603 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -198,7 +198,16 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap)
 
 		val = !val;
 		bri->set_scl(adap, val);
-		ndelay(RECOVERY_NDELAY);
+
+		/*
+		 * If we can set SDA, we will always create STOP here to ensure
+		 * the additional pulses will do no harm. This is achieved by
+		 * letting SDA follow SCL half a cycle later.
+		 */
+		ndelay(RECOVERY_NDELAY / 2);
+		if (bri->set_sda)
+			bri->set_sda(adap, val);
+		ndelay(RECOVERY_NDELAY / 2);
 	}
 
 	/* check if recovery actually succeeded */