[PATCH 4.5 038/124] qlcnic: Fix mailbox completion handling during spurious interrupt

[Greg Kroah-Hartman]

4.5-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Rajesh Borundia <rajesh.borundia@xxxxxxxxxx>

[ Upstream commit 819bfe764dceec2f6b4551768453f374b4c60443 ]

o While the driver is in the middle of a MB completion processing
and it receives a spurious MB interrupt, it is mistaken as a good MB
completion interrupt leading to premature completion of the next MB
request. Fix the driver to guard against this by checking the current
state of MB processing and ignore the spurious interrupt.
Also added a stats counter to record this condition.

Signed-off-by: Rajesh Borundia <rajesh.borundia@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/qlogic/qlcnic/qlcnic.h         |    1 +
 drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.c |   15 +++++++++++----
 drivers/net/ethernet/qlogic/qlcnic/qlcnic_ethtool.c |    3 ++-
 3 files changed, 14 insertions(+), 5 deletions(-)

--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic.h
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic.h
@@ -566,6 +566,7 @@ struct qlcnic_adapter_stats {
 	u64  tx_dma_map_error;
 	u64  spurious_intr;
 	u64  mac_filter_limit_overrun;
+	u64  mbx_spurious_intr;
 };
 
 /*
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.c
@@ -2338,9 +2338,9 @@ static void qlcnic_83xx_handle_link_aen(
 
 static irqreturn_t qlcnic_83xx_handle_aen(int irq, void *data)
 {
+	u32 mask, resp, event, rsp_status = QLC_83XX_MBX_RESPONSE_ARRIVED;
 	struct qlcnic_adapter *adapter = data;
 	struct qlcnic_mailbox *mbx;
-	u32 mask, resp, event;
 	unsigned long flags;
 
 	mbx = adapter->ahw->mailbox;
@@ -2350,10 +2350,14 @@ static irqreturn_t qlcnic_83xx_handle_ae
 		goto out;
 
 	event = readl(QLCNIC_MBX_FW(adapter->ahw, 0));
-	if (event &  QLCNIC_MBX_ASYNC_EVENT)
+	if (event &  QLCNIC_MBX_ASYNC_EVENT) {
 		__qlcnic_83xx_process_aen(adapter);
-	else
-		qlcnic_83xx_notify_mbx_response(mbx);
+	} else {
+		if (mbx->rsp_status != rsp_status)
+			qlcnic_83xx_notify_mbx_response(mbx);
+		else
+			adapter->stats.mbx_spurious_intr++;
+	}
 
 out:
 	mask = QLCRDX(adapter->ahw, QLCNIC_DEF_INT_MASK);
@@ -4053,6 +4057,7 @@ static void qlcnic_83xx_mailbox_worker(s
 	struct list_head *head = &mbx->cmd_q;
 	struct qlcnic_hardware_context *ahw;
 	struct qlcnic_cmd_args *cmd = NULL;
+	unsigned long flags;
 
 	ahw = adapter->ahw;
 
@@ -4062,7 +4067,9 @@ static void qlcnic_83xx_mailbox_worker(s
 			return;
 		}
 
+		spin_lock_irqsave(&mbx->aen_lock, flags);
 		mbx->rsp_status = QLC_83XX_MBX_RESPONSE_WAIT;
+		spin_unlock_irqrestore(&mbx->aen_lock, flags);
 
 		spin_lock(&mbx->queue_lock);
 
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_ethtool.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_ethtool.c
@@ -59,7 +59,8 @@ static const struct qlcnic_stats qlcnic_
 	 QLC_OFF(stats.mac_filter_limit_overrun)},
 	{"spurious intr", QLC_SIZEOF(stats.spurious_intr),
 	 QLC_OFF(stats.spurious_intr)},
-
+	{"mbx spurious intr", QLC_SIZEOF(stats.mbx_spurious_intr),
+	 QLC_OFF(stats.mbx_spurious_intr)},
 };
 
 static const char qlcnic_device_gstrings_stats[][ETH_GSTRING_LEN] = {