i2c: Clear i2c_adapter.dev on adapter removal

Clear i2c_adapter.dev on adapter removal. This makes it possible to
re-add the adapter at a later point, which some drivers
(i2c-amd756-s4882, i2c-nforce2-s4985) actually do.

This fixes a bug reported by John Stultz here:
  http://lkml.org/lkml/2008/7/15/720
and by Ingo Molar there:
  http://lkml.org/lkml/2008/7/16/78

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: John Stultz <johnstul@us.ibm.com>
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 2f150e33c74c9b19ae6f93dc6e1828ebd619d933..72872d1e63efb6c864e49c6bec333081e5e3c3b6 100644 (file)
--- a/drivers/i2c/busses/i2c-amd756-s4882.c
+++ b/drivers/i2c/busses/i2c-amd756-s4882.c
@@ -155,6 +155,16 @@ static int __init amd756_s4882_init(void)
        int i, error;
        union i2c_smbus_data ioconfig;
 
+       /* 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,
+                              I2C_SMBUS_BYTE_DATA, &ioconfig);
+       if (error) {
+               dev_err(&amd756_smbus.dev, "PCA9556 configuration failed\n");
+               error = -EIO;
+               goto ERROR0;
+       }
+
        /* Unregister physical bus */
        error = i2c_del_adapter(&amd756_smbus);
        if (error) {
@@ -198,22 +208,11 @@ static int __init amd756_s4882_init(void)
        s4882_algo[3].smbus_xfer = amd756_access_virt3;
        s4882_algo[4].smbus_xfer = amd756_access_virt4;
 
-       /* Configure the PCA9556 multiplexer */
-       ioconfig.byte = 0x00; /* All I/O to output mode */
-       error = amd756_smbus.algo->smbus_xfer(&amd756_smbus, 0x18, 0,
-                                             I2C_SMBUS_WRITE, 0x03,
-                                             I2C_SMBUS_BYTE_DATA, &ioconfig);
-       if (error) {
-               dev_err(&amd756_smbus.dev, "PCA9556 configuration failed\n");
-               error = -EIO;
-               goto ERROR3;
-       }
-
        /* Register virtual adapters */
        for (i = 0; i < 5; i++) {
                error = i2c_add_adapter(s4882_adapter+i);
                if (error) {
-                       dev_err(&amd756_smbus.dev,
+                       printk(KERN_ERR "i2c-amd756-s4882: "
                               "Virtual adapter %d registration "
                               "failed, module not inserted\n", i);
                        for (i--; i >= 0; i--)
@@ -252,8 +251,8 @@ static void __exit amd756_s4882_exit(void)
 
        /* Restore physical bus */
        if (i2c_add_adapter(&amd756_smbus))
-               dev_err(&amd756_smbus.dev, "Physical bus restoration "
-                       "failed\n");
+               printk(KERN_ERR "i2c-amd756-s4882: "
+                      "Physical bus restoration failed\n");
 }
 
 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");

diff --git a/drivers/i2c/busses/i2c-nforce2-s4985.c b/drivers/i2c/busses/i2c-nforce2-s4985.c
index 6a8995dfd0bb16a755e273d13f0010a6b797aa20..d1a4cbcf2aa49d0a6c60a482de2d69b41080c141 100644 (file)
--- a/drivers/i2c/busses/i2c-nforce2-s4985.c
+++ b/drivers/i2c/busses/i2c-nforce2-s4985.c
@@ -150,6 +150,16 @@ static int __init nforce2_s4985_init(void)
        int i, error;
        union i2c_smbus_data ioconfig;
 
+       /* 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,
+                              I2C_SMBUS_BYTE_DATA, &ioconfig);
+       if (error) {
+               dev_err(&nforce2_smbus->dev, "PCA9556 configuration failed\n");
+               error = -EIO;
+               goto ERROR0;
+       }
+
        /* Unregister physical bus */
        if (!nforce2_smbus)
                return -ENODEV;
@@ -191,24 +201,13 @@ static int __init nforce2_s4985_init(void)
        s4985_algo[3].smbus_xfer = nforce2_access_virt3;
        s4985_algo[4].smbus_xfer = nforce2_access_virt4;
 
-       /* Configure the PCA9556 multiplexer */
-       ioconfig.byte = 0x00; /* All I/O to output mode */
-       error = nforce2_smbus->algo->smbus_xfer(nforce2_smbus, 0x18, 0,
-                                               I2C_SMBUS_WRITE, 0x03,
-                                               I2C_SMBUS_BYTE_DATA, &ioconfig);
-       if (error) {
-               dev_err(&nforce2_smbus->dev, "PCA9556 configuration failed\n");
-               error = -EIO;
-               goto ERROR3;
-       }
-
        /* Register virtual adapters */
        for (i = 0; i < 5; i++) {
                error = i2c_add_adapter(s4985_adapter + i);
                if (error) {
-                       dev_err(&nforce2_smbus->dev,
-                               "Virtual adapter %d registration "
-                               "failed, module not inserted\n", i);
+                       printk(KERN_ERR "i2c-nforce2-s4985: "
+                              "Virtual adapter %d registration "
+                              "failed, module not inserted\n", i);
                        for (i--; i >= 0; i--)
                                i2c_del_adapter(s4985_adapter + i);
                        goto ERROR3;
@@ -245,8 +244,8 @@ static void __exit nforce2_s4985_exit(void)
 
        /* Restore physical bus */
        if (i2c_add_adapter(nforce2_smbus))
-               dev_err(&nforce2_smbus->dev, "Physical bus restoration "
-                       "failed\n");
+               printk(KERN_ERR "i2c-nforce2-s4985: "
+                      "Physical bus restoration failed\n");
 }
 
 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 0a79f7661017b0a548868db95bba17e2d73a2796..7608df83d6d1e0625a8b0de306a799dac62143d3 100644 (file)
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -654,6 +654,10 @@ int i2c_del_adapter(struct i2c_adapter *adap)
 
        dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
 
+       /* Clear the device structure in case this adapter is ever going to be
+          added again */
+       memset(&adap->dev, 0, sizeof(adap->dev));
+
  out_unlock:
        mutex_unlock(&core_lock);
        return res;