tsnep: Add link down PHY loopback support

PHY loopback turns off link state change signalling. Therefore, the
loopback only works if the link is already up before the PHY loopback is
activated.

Ensure that PHY loopback works even if the link is not already up during
activation by calling netif_carrier_on() explicitly.

Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Link: https://lore.kernel.org/r/20240123200151.60848-1-gerhard@engleder-embedded.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/engleder/tsnep_main.c b/drivers/net/ethernet/engleder/tsnep_main.c
index 9aeff2b37a61299587c22dc39b207204c3412543..ae0b8b37b9bf11f0ac9fb509d711068ae4d54cdb 100644 (file)
--- a/drivers/net/ethernet/engleder/tsnep_main.c
+++ b/drivers/net/ethernet/engleder/tsnep_main.c
@@ -229,8 +229,10 @@ static int tsnep_phy_loopback(struct tsnep_adapter *adapter, bool enable)
         * would delay a working loopback anyway, let's ensure that loopback
         * is working immediately by setting link mode directly
         */
-       if (!retval && enable)
+       if (!retval && enable) {
+               netif_carrier_on(adapter->netdev);
                tsnep_set_link_mode(adapter);
+       }
 
        return retval;
 }