diff options
| -rw-r--r-- | drivers/net/dsa/ocelot/felix_vsc9959.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c index 1e82b0d72058..2c812b481778 100644 --- a/drivers/net/dsa/ocelot/felix_vsc9959.c +++ b/drivers/net/dsa/ocelot/felix_vsc9959.c @@ -645,6 +645,27 @@ static void vsc9959_pcs_init_sgmii(struct phy_device *pcs, const struct phylink_link_state *state) { if (link_an_mode == MLO_AN_INBAND) { + int bmsr, bmcr; + + /* Some PHYs like VSC8234 don't like it when AN restarts on + * their system side and they restart line side AN too, going + * into an endless link up/down loop. Don't restart PCS AN if + * link is up already. + * We do check that AN is enabled just in case this is the 1st + * call, PCS detects a carrier but AN is disabled from power on + * or by boot loader. + */ + bmcr = phy_read(pcs, MII_BMCR); + if (bmcr < 0) + return; + + bmsr = phy_read(pcs, MII_BMSR); + if (bmsr < 0) + return; + + if ((bmcr & BMCR_ANENABLE) && (bmsr & BMSR_LSTATUS)) + return; + /* SGMII spec requires tx_config_Reg[15:0] to be exactly 0x4001 * for the MAC PCS in order to acknowledge the AN. */ |