4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Antoine Tenart <antoine.tenart@xxxxxxxxxxx> [ Upstream commit aeeb2e8fdefdd5d257a1446351c70cb3df540199 ] Phylink made an assumption about the carrier state being down when calling phylink_start(). If this assumption isn't satisfied, the internal phylink state could misbehave and a net device could end up not being functional. This patch fixes this by explicitly calling netif_carrier_off() in phylink_start(). Signed-off-by: Antoine Tenart <antoine.tenart@xxxxxxxxxxx> Acked-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/phy/phylink.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/net/phy/phylink.c +++ b/drivers/net/phy/phylink.c @@ -907,6 +907,9 @@ void phylink_start(struct phylink *pl) phylink_an_mode_str(pl->link_an_mode), phy_modes(pl->link_config.interface)); + /* Always set the carrier off */ + netif_carrier_off(pl->netdev); + /* Apply the link configuration to the MAC when starting. This allows * a fixed-link to start with the correct parameters, and also * ensures that we set the appropriate advertisement for Serdes links.