[lvc-project] [PATCH v1 1/3] net/ethtool/ioctl: return -EOPNOTSUPP if we have no phy stats

[Daniil Tatianin]

It's not very useful to copy back an empty ethtool_stats struct and
return 0 if we didn't actually have any stats. This also allows for
further simplification of this function in the future commits.

Signed-off-by: Daniil Tatianin <d-tatianin at yandex-team.ru>
---
 net/ethtool/ioctl.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 57e7238a4136..071e9bf16007 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -2089,11 +2089,15 @@ static int ethtool_get_phy_stats(struct net_device *dev, void __user *useraddr)
 		n_stats = phy_ops->get_sset_count(phydev);
 	else
 		n_stats = ops->get_sset_count(dev, ETH_SS_PHY_STATS);
+
 	if (n_stats < 0)
 		return n_stats;
 	if (n_stats > S32_MAX / sizeof(u64))
 		return -ENOMEM;
-	WARN_ON_ONCE(!n_stats);
+	if (!n_stats) {
+		WARN_ON_ONCE(1);
+		return -EOPNOTSUPP;
+	}
 
 	if (copy_from_user(&stats, useraddr, sizeof(stats)))
 		return -EFAULT;
-- 
2.25.1