iavf: Wait for reset in callbacks which trigger it

There was a fail when trying to add the interface to bonding
right after changing the MTU on the interface. It was caused
by bonding interface unable to open the interface due to
interface being in __RESETTING state because of MTU change.

Add new reset_waitqueue to indicate that reset has finished.

Add waiting for reset to finish in callbacks which trigger hw reset:
iavf_set_priv_flags(), iavf_change_mtu() and iavf_set_ringparam().
We use a 5000ms timeout period because on Hyper-V based systems,
this operation takes around 3000-4000ms. In normal circumstances,
it doesn't take more than 500ms to complete.

Add a function iavf_wait_for_reset() to reuse waiting for reset code and
use it also in iavf_set_channels(), which already waits for reset.
We don't use error handling in iavf_set_channels() as this could
cause the device to be in incorrect state if the reset was scheduled
but hit timeout or the waitng function was interrupted by a signal.

Fixes: 4e5e6b5d9d13 ("iavf: Fix return of set the new channel count")
Signed-off-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Co-developed-by: Dawid Wesierski <dawidx.wesierski@intel.com>
Signed-off-by: Dawid Wesierski <dawidx.wesierski@intel.com>
Signed-off-by: Sylwester Dziedziuch <sylwesterx.dziedziuch@intel.com>
Signed-off-by: Kamil Maziarz <kamil.maziarz@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 50 insertions, 1 deletions

diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index 058e19c6f94a..b89933aa5bfe 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -167,6 +167,45 @@ static struct iavf_adapter *iavf_pdev_to_adapter(struct pci_dev *pdev)
 }
 
 /**
+ * iavf_is_reset_in_progress - Check if a reset is in progress
+ * @adapter: board private structure
+ */
+static bool iavf_is_reset_in_progress(struct iavf_adapter *adapter)
+{
+	if (adapter->state == __IAVF_RESETTING ||
+	    adapter->flags & (IAVF_FLAG_RESET_PENDING |
+			      IAVF_FLAG_RESET_NEEDED))
+		return true;
+
+	return false;
+}
+
+/**
+ * iavf_wait_for_reset - Wait for reset to finish.
+ * @adapter: board private structure
+ *
+ * Returns 0 if reset finished successfully, negative on timeout or interrupt.
+ */
+int iavf_wait_for_reset(struct iavf_adapter *adapter)
+{
+	int ret = wait_event_interruptible_timeout(adapter->reset_waitqueue,
+					!iavf_is_reset_in_progress(adapter),
+					msecs_to_jiffies(5000));
+
+	/* If ret < 0 then it means wait was interrupted.
+	 * If ret == 0 then it means we got a timeout while waiting
+	 * for reset to finish.
+	 * If ret > 0 it means reset has finished.
+	 */
+	if (ret > 0)
+		return 0;
+	else if (ret < 0)
+		return -EINTR;
+	else
+		return -EBUSY;
+}
+
+/**
  * iavf_allocate_dma_mem_d - OS specific memory alloc for shared code
  * @hw:   pointer to the HW structure
  * @mem:  ptr to mem struct to fill out
@@ -3149,6 +3188,7 @@ continue_reset:
 
 	adapter->flags &= ~IAVF_FLAG_REINIT_ITR_NEEDED;
 
+	wake_up(&adapter->reset_waitqueue);
 	mutex_unlock(&adapter->client_lock);
 	mutex_unlock(&adapter->crit_lock);
 
@@ -4313,6 +4353,7 @@ static int iavf_close(struct net_device *netdev)
 static int iavf_change_mtu(struct net_device *netdev, int new_mtu)
 {
 	struct iavf_adapter *adapter = netdev_priv(netdev);
+	int ret = 0;
 
 	netdev_dbg(netdev, "changing MTU from %d to %d\n",
 		   netdev->mtu, new_mtu);
@@ -4325,9 +4366,14 @@ static int iavf_change_mtu(struct net_device *netdev, int new_mtu)
 	if (netif_running(netdev)) {
 		adapter->flags |= IAVF_FLAG_RESET_NEEDED;
 		queue_work(adapter->wq, &adapter->reset_task);
+		ret = iavf_wait_for_reset(adapter);
+		if (ret < 0)
+			netdev_warn(netdev, "MTU change interrupted waiting for reset");
+		else if (ret)
+			netdev_warn(netdev, "MTU change timed out waiting for reset");
 	}
 
-	return 0;
+	return ret;
 }
 
 #define NETIF_VLAN_OFFLOAD_FEATURES	(NETIF_F_HW_VLAN_CTAG_RX | \
@@ -4928,6 +4974,9 @@ static int iavf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	/* Setup the wait queue for indicating transition to down status */
 	init_waitqueue_head(&adapter->down_waitqueue);
 
+	/* Setup the wait queue for indicating transition to running state */
+	init_waitqueue_head(&adapter->reset_waitqueue);
+
 	/* Setup the wait queue for indicating virtchannel events */
 	init_waitqueue_head(&adapter->vc_waitqueue);