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 72872d1e63efb6c864e49c6bec333081e5e3c3b6..8ba2bcf727d31a3ed725a2a9a0baf5a506046da8 100644 (file)
--- 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 d1a4cbcf2aa49d0a6c60a482de2d69b41080c141..29015eb9ca46daee3ca21635c6b1b631aecc90d6 100644 (file)
--- 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");