IB/ipath: Test interrupts at driver startup

All too often, interrupts do not get enabled for our card due to BIOS
misconfiguration and other issues.  This patch checks for that
condition on startup and warns the user.  This patch is based on work
(check LID availability) by Robert Walsh.

Signed-off-by: Arthur Jones <arthur.jones@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index da4a2cf..e397ec0 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -104,6 +104,9 @@
 #define PCI_DEVICE_ID_INFINIPATH_HT 0xd
 #define PCI_DEVICE_ID_INFINIPATH_PE800 0x10
 
+/* Number of seconds before our card status check...  */
+#define STATUS_TIMEOUT 60
+
 static const struct pci_device_id ipath_pci_tbl[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_PATHSCALE, PCI_DEVICE_ID_INFINIPATH_HT) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_PATHSCALE, PCI_DEVICE_ID_INFINIPATH_PE800) },
@@ -119,6 +122,18 @@
 	.id_table = ipath_pci_tbl,
 };
 
+static void ipath_check_status(struct work_struct *work)
+{
+	struct ipath_devdata *dd = container_of(work, struct ipath_devdata,
+						status_work.work);
+
+	/*
+	 * If we don't have any interrupts, let the user know and
+	 * don't bother checking again.
+	 */
+	if (dd->ipath_int_counter == 0)
+		dev_err(&dd->pcidev->dev, "No interrupts detected.\n");
+}
 
 static inline void read_bars(struct ipath_devdata *dd, struct pci_dev *dev,
 			     u32 *bar0, u32 *bar1)
@@ -187,6 +202,8 @@
 	dd->pcidev = pdev;
 	pci_set_drvdata(pdev, dd);
 
+	INIT_DELAYED_WORK(&dd->status_work, ipath_check_status);
+
 	list_add(&dd->ipath_list, &ipath_dev_list);
 
 bail_unlock:
@@ -511,6 +528,9 @@
 	ipath_diag_add(dd);
 	ipath_register_ib_device(dd);
 
+	/* Check that card status in STATUS_TIMEOUT seconds. */
+	schedule_delayed_work(&dd->status_work, HZ * STATUS_TIMEOUT);
+
 	goto bail;
 
 bail_irqsetup:
@@ -638,6 +658,9 @@
 	 */
 	ipath_shutdown_device(dd);
 
+	cancel_delayed_work(&dd->status_work);
+	flush_scheduled_work();
+
 	if (dd->verbs_dev)
 		ipath_unregister_ib_device(dd->verbs_dev);