[PATCH 2/2] ethtool: Call begin() and complete() in __ethtool_get_link_ksettings()

[Kai-Heng Feng <kai.heng.feng@canonical.com>]

Device like igb gets runtime suspended when there's no link partner. We
can't get correct speed under that state:
$ cat /sys/class/net/enp3s0/speed
1000

In addition to that, an error can also be spotted in dmesg:
[  385.991957] igb 0000:03:00.0 enp3s0: PCIe link lost

It's because the igb device doesn't get runtime resumed before calling
get_link_ksettings().

So let's call begin() and complete() like what dev_ethtool() does, to
runtime resume/suspend or power up/down the device properly.

Once this fix is in place, igb can show the speed correctly without link
partner:
$ cat /sys/class/net/enp3s0/speed
-1

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 net/ethtool/ioctl.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 182bffbffa78..c768dbf45fc4 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -423,13 +423,26 @@ struct ethtool_link_usettings {
 int __ethtool_get_link_ksettings(struct net_device *dev,
 				 struct ethtool_link_ksettings *link_ksettings)
 {
+	int rc;
+
 	ASSERT_RTNL();
 
 	if (!dev->ethtool_ops->get_link_ksettings)
 		return -EOPNOTSUPP;
 
+	if (dev->ethtool_ops->begin) {
+		rc = dev->ethtool_ops->begin(dev);
+		if (rc  < 0)
+			return rc;
+	}
+
 	memset(link_ksettings, 0, sizeof(*link_ksettings));
-	return dev->ethtool_ops->get_link_ksettings(dev, link_ksettings);
+	rc = dev->ethtool_ops->get_link_ksettings(dev, link_ksettings);
+
+	if (dev->ethtool_ops->complete)
+		dev->ethtool_ops->complete(dev);
+
+	return rc;
 }
 EXPORT_SYMBOL(__ethtool_get_link_ksettings);
 
-- 
2.17.1