From: Jean Delvare <khali@linux-fr.org>
Date: Sun, 10 Aug 2008 20:56:15 +0000 (+0200)
Subject: i2c: Fix oops on bus multiplexer driver loading
X-Git-Tag: v2.6.27-rc3~54^2~5
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=399d6b26539d83dd734746dc2292d53fbc5807b2;p=linux-2.6

i2c: Fix oops on bus multiplexer driver loading

The two I2C bus multiplexer drivers (i2c-amd756-s4882 and
i2c-nforce2-s4985) make use of the bus they want to multiplex before
checking if it is really present. Swap the instructions to test for
presence first. This fixes a oops reported by Ingo Molnar.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Ingo Molnar <mingo@elte.hu>
---

diff --git a/drivers/i2c/busses/i2c-amd756-s4882.c b/drivers/i2c/busses/i2c-amd756-s4882.c
index 72872d1e63..8ba2bcf727 100644
--- a/drivers/i2c/busses/i2c-amd756-s4882.c
+++ b/drivers/i2c/busses/i2c-amd756-s4882.c
@@ -155,6 +155,9 @@ static int __init amd756_s4882_init(void)
 	int i, error;
 	union i2c_smbus_data ioconfig;
 
+	if (!amd756_smbus.dev.parent)
+		return -ENODEV;
+
 	/* Configure the PCA9556 multiplexer */
 	ioconfig.byte = 0x00; /* All I/O to output mode */
 	error = i2c_smbus_xfer(&amd756_smbus, 0x18, 0, I2C_SMBUS_WRITE, 0x03,
@@ -168,11 +171,7 @@ static int __init amd756_s4882_init(void)
 	/* Unregister physical bus */
 	error = i2c_del_adapter(&amd756_smbus);
 	if (error) {
-		if (error == -EINVAL)
-			error = -ENODEV;
-		else
-			dev_err(&amd756_smbus.dev, "Physical bus removal "
-				"failed\n");
+		dev_err(&amd756_smbus.dev, "Physical bus removal failed\n");
 		goto ERROR0;
 	}
 
diff --git a/drivers/i2c/busses/i2c-nforce2-s4985.c b/drivers/i2c/busses/i2c-nforce2-s4985.c
index d1a4cbcf2a..29015eb9ca 100644
--- a/drivers/i2c/busses/i2c-nforce2-s4985.c
+++ b/drivers/i2c/busses/i2c-nforce2-s4985.c
@@ -150,6 +150,9 @@ static int __init nforce2_s4985_init(void)
 	int i, error;
 	union i2c_smbus_data ioconfig;
 
+	if (!nforce2_smbus)
+		return -ENODEV;
+
 	/* Configure the PCA9556 multiplexer */
 	ioconfig.byte = 0x00; /* All I/O to output mode */
 	error = i2c_smbus_xfer(nforce2_smbus, 0x18, 0, I2C_SMBUS_WRITE, 0x03,
@@ -161,8 +164,6 @@ static int __init nforce2_s4985_init(void)
 	}
 
 	/* Unregister physical bus */
-	if (!nforce2_smbus)
-		return -ENODEV;
 	error = i2c_del_adapter(nforce2_smbus);
 	if (error) {
 		dev_err(&nforce2_smbus->dev, "Physical bus removal failed\n");