i2c: piix4: Fully initialize SB800 before it is registered

This closes a race window where I2C device drivers attempt to access
I2C buses which aren't fully initialized yet.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Christian Fetzer <fetzer.ch@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 9 insertions, 10 deletions

diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 5fd7505b9018..f79a84ef1aa4 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -627,6 +627,7 @@ static struct i2c_adapter *piix4_main_adapters[PIIX4_MAX_ADAPTERS];
 static struct i2c_adapter *piix4_aux_adapter;
 
 static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
+                             bool sb800_main, unsigned short port,
                              const char *name, struct i2c_adapter **padap)
 {
         struct i2c_adapter *adap;
@@ -641,7 +642,8 @@ static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
 
         adap->owner = THIS_MODULE;
         adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
-        adap->algo = &smbus_algorithm;
+        adap->algo = sb800_main ? &piix4_smbus_algorithm_sb800
+                                : &smbus_algorithm;
 
         adapdata = kzalloc(sizeof(*adapdata), GFP_KERNEL);
         if (adapdata == NULL) {
@@ -651,6 +653,8 @@ static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
         }
 
         adapdata->smba = smba;
+        adapdata->sb800_main = sb800_main;
+        adapdata->port = port;
 
         /* set up the sysfs linkage to our parent device */
         adap->dev.parent = &dev->dev;
@@ -680,17 +684,11 @@ static int piix4_add_adapters_sb800(struct pci_dev *dev, unsigned short smba)
         int retval;
 
         for (port = 0; port < PIIX4_MAX_ADAPTERS; port++) {
-                retval = piix4_add_adapter(dev, smba,
+                retval = piix4_add_adapter(dev, smba, true, port,
                                            piix4_main_port_names_sb800[port],
                                            &piix4_main_adapters[port]);
                 if (retval < 0)
                         goto error;
-
-                piix4_main_adapters[port]->algo = &piix4_smbus_algorithm_sb800;
-
-                adapdata = i2c_get_adapdata(piix4_main_adapters[port]);
-                adapdata->sb800_main = true;
-                adapdata->port = port;
         }
 
         return retval;
@@ -748,7 +746,7 @@ static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
                         return retval;
 
                 /* Try to register main SMBus adapter, give up if we can't */
-                retval = piix4_add_adapter(dev, retval, "main",
+                retval = piix4_add_adapter(dev, retval, false, 0, "main",
                                            &piix4_main_adapters[0]);
                 if (retval < 0)
                         return retval;
@@ -775,7 +773,8 @@ static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
         if (retval > 0) {
                 /* Try to add the aux adapter if it exists,
                  * piix4_add_adapter will clean up if this fails */
-                piix4_add_adapter(dev, retval, piix4_aux_port_name_sb800,
+                piix4_add_adapter(dev, retval, false, 0,
+                                  piix4_aux_port_name_sb800,
                                   &piix4_aux_adapter);
         }