i2c: recovery: make pin init look like STOP

When we initialize the pins, make sure it looks like STOP by dividing the delay into halves. It shouldn't matter because SDA is expected to be held low by a device, but for super-safety, let's do it. Signed-off-by: Wolfram Sang <[email protected]> Reviewed-by: Ulrich Hecht <[email protected]> Reviewed-by: Peter Rosin <[email protected]> Signed-off-by: Wolfram Sang <[email protected]>
josf · Jul 20, 2018 · c4ae05b · c4ae05b
1 parent ea3cfbd
commit c4ae05b
Showing 1 changed file with 10 additions and 9 deletions.
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
@@ -190,10 +190,17 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap)
 	if (bri->prepare_recovery)
 		bri->prepare_recovery(adap);
 
+	/*
+	 * If we can set SDA, we will always create a STOP to ensure additional
+	 * pulses will do no harm. This is achieved by letting SDA follow SCL
+	 * half a cycle later. Check the 'incomplete_write_byte' fault injector
+	 * for details.
+	 */
 	bri->set_scl(adap, scl);
+	ndelay(RECOVERY_NDELAY / 2);
 	if (bri->set_sda)
-		bri->set_sda(adap, 1);
-	ndelay(RECOVERY_NDELAY);
+		bri->set_sda(adap, scl);
+	ndelay(RECOVERY_NDELAY / 2);
 
 	/*
 	 * By this time SCL is high, as we need to give 9 falling-rising edges
@@ -211,13 +218,7 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap)
 
 		scl = !scl;
 		bri->set_scl(adap, scl);
-
-		/*
-		 * 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. Check the
-		 * 'incomplete_write_byte' fault injector for details.
-		 */
+		/* Creating STOP again, see above */
 		ndelay(RECOVERY_NDELAY / 2);
 		if (bri->set_sda)
 			bri->set_sda(adap, scl);