ethtool: Do not report link partner advertising flags if set to 0

Only some drivers (and none before kernel version 2.6.31) currently
set these flags.  When the flags are equal to 0 and so we don't know
what the link partner advertised, don't report anything.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/ethtool.c b/ethtool.c
index 10dfc80..298b690 100644
--- a/ethtool.c
+++ b/ethtool.c
@@ -948,7 +948,9 @@ static int dump_ecmd(struct ethtool_cmd *ep)
 
 	dump_supported(ep);
 	dump_advertised(ep, "Advertised", ep->advertising);
-	dump_advertised(ep, "Link partner advertised", ep->lp_advertising);
+	if (ep->lp_advertising)
+		dump_advertised(ep, "Link partner advertised",
+				ep->lp_advertising);
 
 	fprintf(stdout, "	Speed: ");
 	speed = ethtool_cmd_speed(ep);