diff mbox series

ibmvnic: Clear pending interrupt after device reset

Message ID 1523836416-16531-1-git-send-email-tlfalcon@linux.vnet.ibm.com
State Accepted, archived
Delegated to: David Miller
Headers show
Series ibmvnic: Clear pending interrupt after device reset | expand

Commit Message

Thomas Falcon April 15, 2018, 11:53 p.m. UTC
Due to a firmware bug, the hypervisor can send an interrupt to a
transmit or receive queue just prior to a partition migration, not
allowing the device enough time to handle it and send an EOI. When
the partition migrates, the interrupt is lost but an "EOI-pending"
flag for the interrupt line is still set in firmware. No further
interrupts will be sent until that flag is cleared, effectively
freezing that queue. To workaround this, the driver will disable the
hardware interrupt and send an H_EOI signal prior to re-enabling it.
This will flush the pending EOI and allow the driver to continue
operation.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

Comments

David Miller April 16, 2018, 12:55 a.m. UTC | #1
From: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Date: Sun, 15 Apr 2018 18:53:36 -0500

> Due to a firmware bug, the hypervisor can send an interrupt to a
> transmit or receive queue just prior to a partition migration, not
> allowing the device enough time to handle it and send an EOI. When
> the partition migrates, the interrupt is lost but an "EOI-pending"
> flag for the interrupt line is still set in firmware. No further
> interrupts will be sent until that flag is cleared, effectively
> freezing that queue. To workaround this, the driver will disable the
> hardware interrupt and send an H_EOI signal prior to re-enabling it.
> This will flush the pending EOI and allow the driver to continue
> operation.
> 
> Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>

Hey Thomas, I see two copies of this patch posted.  Any special
reason for that?

Thanks.
David Miller April 16, 2018, 3:26 p.m. UTC | #2
From: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Date: Sun, 15 Apr 2018 18:53:36 -0500

> Due to a firmware bug, the hypervisor can send an interrupt to a
> transmit or receive queue just prior to a partition migration, not
> allowing the device enough time to handle it and send an EOI. When
> the partition migrates, the interrupt is lost but an "EOI-pending"
> flag for the interrupt line is still set in firmware. No further
> interrupts will be sent until that flag is cleared, effectively
> freezing that queue. To workaround this, the driver will disable the
> hardware interrupt and send an H_EOI signal prior to re-enabling it.
> This will flush the pending EOI and allow the driver to continue
> operation.
> 
> Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>

Applied, thanks Thomas.
diff mbox series

Patch

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index f84a920..ef7995fc 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1034,16 +1034,14 @@  static int __ibmvnic_open(struct net_device *netdev)
 		netdev_dbg(netdev, "Enabling rx_scrq[%d] irq\n", i);
 		if (prev_state == VNIC_CLOSED)
 			enable_irq(adapter->rx_scrq[i]->irq);
-		else
-			enable_scrq_irq(adapter, adapter->rx_scrq[i]);
+		enable_scrq_irq(adapter, adapter->rx_scrq[i]);
 	}
 
 	for (i = 0; i < adapter->req_tx_queues; i++) {
 		netdev_dbg(netdev, "Enabling tx_scrq[%d] irq\n", i);
 		if (prev_state == VNIC_CLOSED)
 			enable_irq(adapter->tx_scrq[i]->irq);
-		else
-			enable_scrq_irq(adapter, adapter->tx_scrq[i]);
+		enable_scrq_irq(adapter, adapter->tx_scrq[i]);
 	}
 
 	rc = set_link_state(adapter, IBMVNIC_LOGICAL_LNK_UP);
@@ -1184,6 +1182,7 @@  static void ibmvnic_disable_irqs(struct ibmvnic_adapter *adapter)
 			if (adapter->tx_scrq[i]->irq) {
 				netdev_dbg(netdev,
 					   "Disabling tx_scrq[%d] irq\n", i);
+				disable_scrq_irq(adapter, adapter->tx_scrq[i]);
 				disable_irq(adapter->tx_scrq[i]->irq);
 			}
 	}
@@ -1193,6 +1192,7 @@  static void ibmvnic_disable_irqs(struct ibmvnic_adapter *adapter)
 			if (adapter->rx_scrq[i]->irq) {
 				netdev_dbg(netdev,
 					   "Disabling rx_scrq[%d] irq\n", i);
+				disable_scrq_irq(adapter, adapter->rx_scrq[i]);
 				disable_irq(adapter->rx_scrq[i]->irq);
 			}
 		}
@@ -2601,12 +2601,19 @@  static int enable_scrq_irq(struct ibmvnic_adapter *adapter,
 {
 	struct device *dev = &adapter->vdev->dev;
 	unsigned long rc;
+	u64 val;
 
 	if (scrq->hw_irq > 0x100000000ULL) {
 		dev_err(dev, "bad hw_irq = %lx\n", scrq->hw_irq);
 		return 1;
 	}
 
+	val = (0xff000000) | scrq->hw_irq;
+	rc = plpar_hcall_norets(H_EOI, val);
+	if (rc)
+		dev_err(dev, "H_EOI FAILED irq 0x%llx. rc=%ld\n",
+			val, rc);
+
 	rc = plpar_hcall_norets(H_VIOCTL, adapter->vdev->unit_address,
 				H_ENABLE_VIO_INTERRUPT, scrq->hw_irq, 0, 0);
 	if (rc)