RE: [PATCH 5/5] net/hyperv: Call netif_carrier_off() after register_netdev()

-----Original Message-----
From: Ilya Shchepetkov [mailto:shchepetkov@ispras.ru]
Sent: Tuesday, August 14, 2012 6:29 AM
To: KY Srinivasan
Cc: Ilya Shchepetkov; Haiyang Zhang; David S. Miller;
devel@linuxdriverproject.org; netdev@vger.kernel.org; linux-
kernel@vger.kernel.org; ldv-project@ispras.ru
Subject: [PATCH 5/5] net/hyperv: Call netif_carrier_off() after
register_netdev()

For carrier detection to work properly when binding the driver with a
cable unplugged, netif_carrier_off() should be called after
register_netdev(), not before.

Calling netif_carrier_off() before register_netdev() was causing the
network interface to miss a linkwatch pending event leading to an
inconsistent state if the link is not up when interface is initialized.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Ilya Shchepetkov <redacted>
---
 drivers/net/hyperv/netvsc_drv.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c

b/drivers/net/hyperv/netvsc_drv.c
index 8c5a1c4..5734ad0 100644

--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c

@@ -416,9 +416,6 @@ static int netvsc_probe(struct hv_device *dev,
 	if (!net)
 		return -ENOMEM;

-	/* Set initial state */
-	netif_carrier_off(net);
-
 	net_device_ctx = netdev_priv(net);
 	net_device_ctx->device_ctx = dev;
 	hv_set_drvdata(dev, net);

@@ -441,6 +438,9 @@ static int netvsc_probe(struct hv_device *dev,
 		goto out;
 	}

+	/* Set initial state */
+	netif_carrier_off(net);
+
 	/* Notify the netvsc driver of the new device */
 	device_info.ring_size = ring_size;
 	ret = rndis_filter_device_add(dev, &device_info);