[ofa-general] [PATCH 08/20] IB/ipath - fix check for no interrupts to reliably fallback to INTx

[Ralph Campbell]

From: Dave Olson <dave.olson at qlogic.com>

Newer HCAs support MSI interrupts and also INTx interrupts.
Fix the code so that INTx can be reliably enabled if MSI interrupts
are not working.

Signed-off-by: Dave Olson <dave.olson at qlogic.com>
---

 drivers/infiniband/hw/ipath/ipath_driver.c    |   23 +++-------------
 drivers/infiniband/hw/ipath/ipath_init_chip.c |   36 +++++++++++++++++++++++++
 drivers/infiniband/hw/ipath/ipath_kernel.h    |    5 +--
 3 files changed, 42 insertions(+), 22 deletions(-)

diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index 53f8ae4..b4a69ef 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -138,19 +138,6 @@ static struct pci_driver ipath_driver = {
 	},
 };
 
-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)
 {
@@ -218,8 +205,6 @@ static struct ipath_devdata *ipath_alloc_devdata(struct pci_dev *pdev)
 	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:
@@ -620,9 +605,6 @@ static int __devinit ipath_init_one(struct pci_dev *pdev,
 	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:
@@ -753,7 +735,6 @@ static void __devexit ipath_remove_one(struct pci_dev *pdev)
 	 */
 	ipath_shutdown_device(dd);
 
-	cancel_delayed_work(&dd->status_work);
 	flush_scheduled_work();
 
 	if (dd->verbs_dev)
@@ -2195,6 +2176,10 @@ void ipath_shutdown_device(struct ipath_devdata *dd)
 		del_timer_sync(&dd->ipath_stats_timer);
 		dd->ipath_stats_timer_active = 0;
 	}
+	if (dd->ipath_intrchk_timer.data) {
+		del_timer_sync(&dd->ipath_intrchk_timer);
+		dd->ipath_intrchk_timer.data = 0;
+	}
 
 	/*
 	 * clear all interrupts and errors, so that the next time the driver
diff --git a/drivers/infiniband/hw/ipath/ipath_init_chip.c b/drivers/infiniband/hw/ipath/ipath_init_chip.c
index 1adafa9..0db19c1 100644
--- a/drivers/infiniband/hw/ipath/ipath_init_chip.c
+++ b/drivers/infiniband/hw/ipath/ipath_init_chip.c
@@ -665,6 +665,28 @@ done:
 	return ret;
 }
 
+static void verify_interrupt(unsigned long opaque)
+{
+	struct ipath_devdata *dd = (struct ipath_devdata *) opaque;
+
+	if (!dd)
+		return; /* being torn down */
+
+	/*
+	 * If we don't have any interrupts, let the user know and
+	 * don't bother checking again.
+	 */
+	if (dd->ipath_int_counter == 0) {
+		if (!dd->ipath_f_intr_fallback(dd))
+			dev_err(&dd->pcidev->dev, "No interrupts detected, "
+				"not usable.\n");
+		else /* re-arm the timer to see if fallback works */
+			mod_timer(&dd->ipath_intrchk_timer, jiffies + HZ/2);
+	} else
+		ipath_cdbg(VERBOSE, "%u interrupts at timer check\n",
+			dd->ipath_int_counter);
+}
+
 /**
  * ipath_init_chip - do the actual initialization sequence on the chip
  * @dd: the infinipath device
@@ -968,6 +990,20 @@ done:
 					 0ULL);
 			/* chip is usable; mark it as initialized */
 			*dd->ipath_statusp |= IPATH_STATUS_INITTED;
+
+			/*
+			 * setup to verify we get an interrupt, and fallback
+			 * to an alternate if necessary and possible
+			 */
+			if (!reinit) {
+				init_timer(&dd->ipath_intrchk_timer);
+				dd->ipath_intrchk_timer.function =
+					verify_interrupt;
+				dd->ipath_intrchk_timer.data =
+					(unsigned long) dd;
+			}
+			dd->ipath_intrchk_timer.expires = jiffies + HZ/2;
+			add_timer(&dd->ipath_intrchk_timer);
 		} else
 			ipath_dev_err(dd, "No interrupts enabled, couldn't "
 				      "setup interrupt address\n");
diff --git a/drivers/infiniband/hw/ipath/ipath_kernel.h b/drivers/infiniband/hw/ipath/ipath_kernel.h
index e96eec2..90bbbc7 100644
--- a/drivers/infiniband/hw/ipath/ipath_kernel.h
+++ b/drivers/infiniband/hw/ipath/ipath_kernel.h
@@ -426,6 +426,8 @@ struct ipath_devdata {
 	struct class_device *diag_class_dev;
 	/* timer used to prevent stats overflow, error throttling, etc. */
 	struct timer_list ipath_stats_timer;
+	/* timer to verify interrupts work, and fallback if possible */
+	struct timer_list ipath_intrchk_timer;
 	void *ipath_dummy_hdrq;	/* used after port close */
 	dma_addr_t ipath_dummy_hdrq_phys;
 
@@ -629,9 +631,6 @@ struct ipath_devdata {
 	u32 ipath_overrun_thresh_errs;
 	u32 ipath_lli_errs;
 
-	/* status check work */
-	struct delayed_work status_work;
-
 	/*
 	 * Not all devices managed by a driver instance are the same
 	 * type, so these fields must be per-device.