hwmon: Let w83781d and lm78 load again

Let the w83781d and lm78 hardware monitoring drivers load even when
no chip was detected at the ISA address. There can still be supported
chips connected to an I2C bus or SMBus.

This fixes bug #7293.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/hwmon/lm78.c

@@ -815,18 +815,18 @@ static int __init sm_lm78_init(void)
 	if (res)
 		return res;
 
-	res = i2c_isa_add_driver(&lm78_isa_driver);
-	if (res) {
-		i2c_del_driver(&lm78_driver);
-		return res;
-	}
+	/* Don't exit if this one fails, we still want the I2C variants
+	   to work! */
+	if (i2c_isa_add_driver(&lm78_isa_driver))
+		isa_address = 0;
 
 	return 0;
 }
 
 static void __exit sm_lm78_exit(void)
 {
-	i2c_isa_del_driver(&lm78_isa_driver);
+	if (isa_address)
+		i2c_isa_del_driver(&lm78_isa_driver);
 	i2c_del_driver(&lm78_driver);
 }
 

drivers/hwmon/w83781d.c

@@ -1685,11 +1685,10 @@ sensors_w83781d_init(void)
 	if (res)
 		return res;
 
-	res = i2c_isa_add_driver(&w83781d_isa_driver);
-	if (res) {
-		i2c_del_driver(&w83781d_driver);
-		return res;
-	}
+	/* Don't exit if this one fails, we still want the I2C variants
+	   to work! */
+	if (i2c_isa_add_driver(&w83781d_isa_driver))
+		isa_address = 0;
 
 	return 0;
 }
@@ -1697,7 +1696,8 @@ sensors_w83781d_init(void)
 static void __exit
 sensors_w83781d_exit(void)
 {
-	i2c_isa_del_driver(&w83781d_isa_driver);
+	if (isa_address)
+		i2c_isa_del_driver(&w83781d_isa_driver);
 	i2c_del_driver(&w83781d_driver);
 }
 

drivers/i2c/busses/i2c-isa.c

@@ -91,7 +91,7 @@ int i2c_isa_add_driver(struct i2c_driver *driver)
 	/* Now look for clients */
 	res = driver->attach_adapter(&isa_adapter);
 	if (res) {
-		dev_err(&isa_adapter.dev,
+		dev_dbg(&isa_adapter.dev,
 			"Driver %s failed to attach adapter, unregistering\n",
 			driver->driver.name);
 		driver_unregister(&driver->driver);