IB/ipath: Initialize diagpkt file on device init only

Don't attempt to set up the diagpkt device in the module init code.
Instead, wait until a piece of hardware is initialized.  Fixes a
problem when loading the ib_ipath module when no InfiniPath hardware
is present: modprobe would go into the D state and stay there.

Signed-off-by: Robert Walsh <robert.walsh@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 38 insertions, 27 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_diag.c b/drivers/infiniband/hw/ipath/ipath_diag.c
index 29958b6e0214..28c087b824c2 100644
--- a/drivers/infiniband/hw/ipath/ipath_diag.c
+++ b/drivers/infiniband/hw/ipath/ipath_diag.c
@@ -67,19 +67,54 @@ static struct file_operations diag_file_ops = {
         .release = ipath_diag_release
 };
 
+static ssize_t ipath_diagpkt_write(struct file *fp,
+                                   const char __user *data,
+                                   size_t count, loff_t *off);
+
+static struct file_operations diagpkt_file_ops = {
+        .owner = THIS_MODULE,
+        .write = ipath_diagpkt_write,
+};
+
+static atomic_t diagpkt_count = ATOMIC_INIT(0);
+static struct cdev *diagpkt_cdev;
+static struct class_device *diagpkt_class_dev;
+
 int ipath_diag_add(struct ipath_devdata *dd)
 {
         char name[16];
+        int ret = 0;
+
+        if (atomic_inc_return(&diagpkt_count) == 1) {
+                ret = ipath_cdev_init(IPATH_DIAGPKT_MINOR,
+                                      "ipath_diagpkt", &diagpkt_file_ops,
+                                      &diagpkt_cdev, &diagpkt_class_dev);
+
+                if (ret) {
+                        ipath_dev_err(dd, "Couldn't create ipath_diagpkt "
+                                      "device: %d", ret);
+                        goto done;
+                }
+        }
 
         snprintf(name, sizeof(name), "ipath_diag%d", dd->ipath_unit);
 
-        return ipath_cdev_init(IPATH_DIAG_MINOR_BASE + dd->ipath_unit, name,
-                               &diag_file_ops, &dd->diag_cdev,
-                               &dd->diag_class_dev);
+        ret = ipath_cdev_init(IPATH_DIAG_MINOR_BASE + dd->ipath_unit, name,
+                              &diag_file_ops, &dd->diag_cdev,
+                              &dd->diag_class_dev);
+        if (ret)
+                ipath_dev_err(dd, "Couldn't create %s device: %d",
+                              name, ret);
+
+done:
+        return ret;
 }
 
 void ipath_diag_remove(struct ipath_devdata *dd)
 {
+        if (atomic_dec_and_test(&diagpkt_count))
+                ipath_cdev_cleanup(&diagpkt_cdev, &diagpkt_class_dev);
+
         ipath_cdev_cleanup(&dd->diag_cdev, &dd->diag_class_dev);
 }
 
@@ -275,30 +310,6 @@ bail:
         return ret;
 }
 
-static ssize_t ipath_diagpkt_write(struct file *fp,
-                                   const char __user *data,
-                                   size_t count, loff_t *off);
-
-static struct file_operations diagpkt_file_ops = {
-        .owner = THIS_MODULE,
-        .write = ipath_diagpkt_write,
-};
-
-static struct cdev *diagpkt_cdev;
-static struct class_device *diagpkt_class_dev;
-
-int __init ipath_diagpkt_add(void)
-{
-        return ipath_cdev_init(IPATH_DIAGPKT_MINOR,
-                               "ipath_diagpkt", &diagpkt_file_ops,
-                               &diagpkt_cdev, &diagpkt_class_dev);
-}
-
-void __exit ipath_diagpkt_remove(void)
-{
-        ipath_cdev_cleanup(&diagpkt_cdev, &diagpkt_class_dev);
-}
-
 /**
  * ipath_diagpkt_write - write an IB packet
  * @fp: the diag data device file pointer