Sleep time is added to ensure the phy to be ready after loopback bit was set. This to prevent the phy loopback test from failing.

Fixes: 020a45aff119 ("net: phy: marvell: add Marvell specific PHY loopback") Cc: stable@vger.kernel.org # 5.15.x Signed-off-by: Muhammad Husaini Zulkifli muhammad.husaini.zulkifli@intel.com Signed-off-by: Aminuddin Jamaluddin aminuddin.jamaluddin@intel.com

--- V2 -> V3: Fix review comments from Jakub V1: https://patchwork.kernel.org/project/netdevbpf/patch/20220825082238.11056-1-... --- --- drivers/net/phy/marvell.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c index a3e810705ce2..860610ba4d00 100644 --- a/drivers/net/phy/marvell.c +++ b/drivers/net/phy/marvell.c @@ -2015,14 +2015,16 @@ static int m88e1510_loopback(struct phy_device *phydev, bool enable) if (err < 0) return err;

- /* FIXME: Based on trial and error test, it seem 1G need to have - * delay between soft reset and loopback enablement. - */ - if (phydev->speed == SPEED_1000) - msleep(1000); + err = phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK, + BMCR_LOOPBACK);

- return phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK, - BMCR_LOOPBACK); + if (!err) { + /* It takes some time for PHY device to switch + * into/out-of loopback mode. + */ + msleep(1000); + } + return err; } else { err = phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK, 0); if (err < 0)