From: Qi Zhang <qi.z.zhang@intel.com>
Date: Wed, 27 Dec 2017 20:22:30 +0000 (-0500)
Subject: net/e1000: fix mailbox interrupt handler
X-Git-Tag: spdx-start~319
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=dd18b06a32833543c6951b6206ac39896eaac154;p=dpdk.git

net/e1000: fix mailbox interrupt handler

Mailbox interrupt handler only takecare of the PF reset notification,
for other message mbx->ops.read should not be called since it gets
chance to break the foreground VF to PF communication.

Fixes: 316f4f1adc2e ("net/igb: support VF mailbox interrupt for link up/down")
Cc: stable@dpdk.org

Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Acked-by: Wei Dai <wei.dai@intel.com>
---

diff --git a/drivers/net/e1000/igb_ethdev.c b/drivers/net/e1000/igb_ethdev.c
index ae43adeb1e..077e09400d 100644
--- a/drivers/net/e1000/igb_ethdev.c
+++ b/drivers/net/e1000/igb_ethdev.c
@@ -2961,13 +2961,17 @@ void igbvf_mbx_process(struct rte_eth_dev *dev)
 	struct e1000_mbx_info *mbx = &hw->mbx;
 	u32 in_msg = 0;
 
-	if (mbx->ops.read(hw, &in_msg, 1, 0))
-		return;
+	/* peek the message first */
+	in_msg = E1000_READ_REG(hw, E1000_VMBMEM(0));
 
 	/* PF reset VF event */
-	if (in_msg == E1000_PF_CONTROL_MSG)
+	if (in_msg == E1000_PF_CONTROL_MSG) {
+		/* dummy mbx read to ack pf */
+		if (mbx->ops.read(hw, &in_msg, 1, 0))
+			return;
 		_rte_eth_dev_callback_process(dev, RTE_ETH_EVENT_INTR_RESET,
 					      NULL);
+	}
 }
 
 static int