[PATCH v2 net-next 0/2] ionic watchdog training

[PATCH v2 net-next 0/2] ionic watchdog training

[Shannon Nelson]

Our link watchdog displayed a couple of unfriendly behaviors in some recent
stress testing.  These patches change the startup and stop timing in order
to be sure that expected structures are ready to be used by the watchdog.

Shannon Nelson (2):
  ionic: stop watchdog timer earlier on remove
  ionic: prevent early watchdog check

v2: rebased to fold in recent changes

 drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c |  5 +++--
 drivers/net/ethernet/pensando/ionic/ionic_dev.c     | 10 ++++------
 drivers/net/ethernet/pensando/ionic/ionic_dev.h     |  1 -
 3 files changed, 7 insertions(+), 9 deletions(-)

-- 
2.17.1

[PATCH v2 net-next 1/2] ionic: stop watchdog timer earlier on remove

[Shannon Nelson]

We need to be better at making sure we don't have a link check
watchdog go off while we're shutting things down, so let's stop
the timer as soon as we start the remove.

Meanwhile, since that was the only thing in
ionic_dev_teardown(), simplify and remove that function.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
---
 drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c | 5 +++--
 drivers/net/ethernet/pensando/ionic/ionic_dev.c     | 5 -----
 drivers/net/ethernet/pensando/ionic/ionic_dev.h     | 1 -
 3 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c b/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c
index d1d6fb6669e5..2749ce009ebc 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c
@@ -350,7 +350,7 @@ static int ionic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 err_out_reset:
 	ionic_reset(ionic);
 err_out_teardown:
-	ionic_dev_teardown(ionic);
+	del_timer_sync(&ionic->watchdog_timer);
 	pci_clear_master(pdev);
 	/* Don't fail the probe for these errors, keep
 	 * the hw interface around for inspection
@@ -378,6 +378,8 @@ static void ionic_remove(struct pci_dev *pdev)
 	if (!ionic)
 		return;
 
+	del_timer_sync(&ionic->watchdog_timer);
+
 	if (ionic->lif) {
 		ionic_devlink_unregister(ionic);
 		ionic_lif_unregister(ionic->lif);
@@ -389,7 +391,6 @@ static void ionic_remove(struct pci_dev *pdev)
 
 	ionic_port_reset(ionic);
 	ionic_reset(ionic);
-	ionic_dev_teardown(ionic);
 	pci_clear_master(pdev);
 	ionic_unmap_bars(ionic);
 	pci_release_regions(pdev);
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.c b/drivers/net/ethernet/pensando/ionic/ionic_dev.c
index a02f710200da..16b6b65e8319 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_dev.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.c
@@ -98,11 +98,6 @@ int ionic_dev_setup(struct ionic *ionic)
 	return 0;
 }
 
-void ionic_dev_teardown(struct ionic *ionic)
-{
-	del_timer_sync(&ionic->watchdog_timer);
-}
-
 /* Devcmd Interface */
 int ionic_heartbeat_check(struct ionic *ionic)
 {
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.h b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
index 8842dc4a716f..c109cd5a0471 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h
+++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
@@ -283,7 +283,6 @@ static inline bool ionic_q_has_space(struct ionic_queue *q, unsigned int want)
 
 void ionic_init_devinfo(struct ionic *ionic);
 int ionic_dev_setup(struct ionic *ionic);
-void ionic_dev_teardown(struct ionic *ionic);
 
 void ionic_dev_cmd_go(struct ionic_dev *idev, union ionic_dev_cmd *cmd);
 u8 ionic_dev_cmd_status(struct ionic_dev *idev);
-- 
2.17.1

[PATCH v2 net-next 2/2] ionic: prevent early watchdog check

[Shannon Nelson]

In one corner case scenario, the driver device lif setup can
get delayed such that the ionic_watchdog_cb() timer goes off
before the ionic->lif is set, thus causing a NULL pointer panic.
We catch the problem by checking for a NULL lif just a little
earlier in the callback.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
---
 drivers/net/ethernet/pensando/ionic/ionic_dev.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.c b/drivers/net/ethernet/pensando/ionic/ionic_dev.c
index 16b6b65e8319..545c99b15df8 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_dev.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.c
@@ -19,9 +19,12 @@ static void ionic_watchdog_cb(struct timer_list *t)
 	mod_timer(&ionic->watchdog_timer,
 		  round_jiffies(jiffies + ionic->watchdog_period));
 
+	if (!ionic->lif)
+		return;
+
 	hb = ionic_heartbeat_check(ionic);
 
-	if (hb >= 0 && ionic->lif)
+	if (hb >= 0)
 		ionic_link_status_check_request(ionic->lif, false);
 }
 
-- 
2.17.1

Re: [PATCH v2 net-next 0/2] ionic watchdog training

[David Miller]

From: Shannon Nelson <snelson@pensando.io>
Date: Wed, 30 Sep 2020 10:48:26 -0700

> Our link watchdog displayed a couple of unfriendly behaviors in some recent
> stress testing.  These patches change the startup and stop timing in order
> to be sure that expected structures are ready to be used by the watchdog.

Series applied, thanks.