1 files changed, 43 insertions, 31 deletions

diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index bedc6c1b6fa5..7e315b7f8700 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -309,6 +309,7 @@ struct hvcs_struct {
 
 static LIST_HEAD(hvcs_structs);
 static DEFINE_SPINLOCK(hvcs_structs_lock);
+static DEFINE_MUTEX(hvcs_init_mutex);
 
 static void hvcs_unthrottle(struct tty_struct *tty);
 static void hvcs_throttle(struct tty_struct *tty);
@@ -340,6 +341,7 @@ static int __devinit hvcs_probe(struct vio_dev *dev,
 static int __devexit hvcs_remove(struct vio_dev *dev);
 static int __init hvcs_module_init(void);
 static void __exit hvcs_module_exit(void);
+static int __devinit hvcs_initialize(void);
 
 #define HVCS_SCHED_READ 0x00000001
 #define HVCS_QUICK_READ 0x00000002
@@ -762,7 +764,7 @@ static int __devinit hvcs_probe(
         const struct vio_device_id *id)
 {
         struct hvcs_struct *hvcsd;
-        int index;
+        int index, rc;
         int retval;
 
         if (!dev || !id) {
@@ -770,6 +772,13 @@ static int __devinit hvcs_probe(
                 return -EPERM;
         }
 
+        /* Make sure we are properly initialized */
+        rc = hvcs_initialize();
+        if (rc) {
+                pr_err("HVCS: Failed to initialize core driver.\n");
+                return rc;
+        }
+
         /* early to avoid cleanup on failure */
         index = hvcs_get_index();
         if (index < 0) {
@@ -1464,12 +1473,15 @@ static void hvcs_free_index_list(void)
         hvcs_index_count = 0;
 }
 
-static int __init hvcs_module_init(void)
+static int __devinit hvcs_initialize(void)
 {
-        int rc;
-        int num_ttys_to_alloc;
+        int rc, num_ttys_to_alloc;
 
-        printk(KERN_INFO "Initializing %s\n", hvcs_driver_string);
+        mutex_lock(&hvcs_init_mutex);
+        if (hvcs_task) {
+                mutex_unlock(&hvcs_init_mutex);
+                return 0;
+        }
 
         /* Has the user specified an overload with an insmod param? */
         if (hvcs_parm_num_devs <= 0 ||
@@ -1528,35 +1540,13 @@ static int __init hvcs_module_init(void)
 
         hvcs_task = kthread_run(khvcsd, NULL, "khvcsd");
         if (IS_ERR(hvcs_task)) {
-                printk(KERN_ERR "HVCS: khvcsd creation failed.  Driver not loaded.\n");
+                printk(KERN_ERR "HVCS: khvcsd creation failed.\n");
                 rc = -EIO;
                 goto kthread_fail;
         }
-
-        rc = vio_register_driver(&hvcs_vio_driver);
-        if (rc) {
-                printk(KERN_ERR "HVCS: can't register vio driver\n");
-                goto vio_fail;
-        }
-
-        /*
-         * This needs to be done AFTER the vio_register_driver() call or else
-         * the kobjects won't be initialized properly.
-         */
-        rc = driver_create_file(&(hvcs_vio_driver.driver), &driver_attr_rescan);
-        if (rc) {
-                printk(KERN_ERR "HVCS: sysfs attr create failed\n");
-                goto attr_fail;
-        }
-
-        printk(KERN_INFO "HVCS: driver module inserted.\n");
-
+        mutex_unlock(&hvcs_init_mutex);
         return 0;
 
-attr_fail:
-        vio_unregister_driver(&hvcs_vio_driver);
-vio_fail:
-        kthread_stop(hvcs_task);
 kthread_fail:
         kfree(hvcs_pi_buff);
 buff_alloc_fail:
@@ -1566,15 +1556,39 @@ register_fail:
 index_fail:
         put_tty_driver(hvcs_tty_driver);
         hvcs_tty_driver = NULL;
+        mutex_unlock(&hvcs_init_mutex);
         return rc;
 }
 
+static int __init hvcs_module_init(void)
+{
+        int rc = vio_register_driver(&hvcs_vio_driver);
+        if (rc) {
+                printk(KERN_ERR "HVCS: can't register vio driver\n");
+                return rc;
+        }
+
+        pr_info("HVCS: Driver registered.\n");
+
+        /* This needs to be done AFTER the vio_register_driver() call or else
+         * the kobjects won't be initialized properly.
+         */
+        rc = driver_create_file(&(hvcs_vio_driver.driver), &driver_attr_rescan);
+        if (rc)
+                pr_warning(KERN_ERR "HVCS: Failed to create rescan file (err %d)\n", rc);
+
+        return 0;
+}
+
 static void __exit hvcs_module_exit(void)
 {
         /*
          * This driver receives hvcs_remove callbacks for each device upon
          * module removal.
          */
+        vio_unregister_driver(&hvcs_vio_driver);
+        if (!hvcs_task)
+                return;
 
         /*
          * This synchronous operation  will wake the khvcsd kthread if it is
@@ -1589,8 +1603,6 @@ static void __exit hvcs_module_exit(void)
 
         driver_remove_file(&hvcs_vio_driver.driver, &driver_attr_rescan);
 
-        vio_unregister_driver(&hvcs_vio_driver);
-
         tty_unregister_driver(hvcs_tty_driver);
 
         hvcs_free_index_list();