diff options
Diffstat (limited to 'target/linux/layerscape/patches-5.4/701-net-0402-drivers-net-dsa-felix-don-t-restart-PCS-SGMII-AN-if-.patch')
| -rw-r--r-- | target/linux/layerscape/patches-5.4/701-net-0402-drivers-net-dsa-felix-don-t-restart-PCS-SGMII-AN-if-.patch | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/target/linux/layerscape/patches-5.4/701-net-0402-drivers-net-dsa-felix-don-t-restart-PCS-SGMII-AN-if-.patch b/target/linux/layerscape/patches-5.4/701-net-0402-drivers-net-dsa-felix-don-t-restart-PCS-SGMII-AN-if-.patch new file mode 100644 index 0000000000..5008ca5c77 --- /dev/null +++ b/target/linux/layerscape/patches-5.4/701-net-0402-drivers-net-dsa-felix-don-t-restart-PCS-SGMII-AN-if-.patch @@ -0,0 +1,41 @@ +From 2a2ccfa44e56c45dfd1230f6efb3ec0a4a677f0a Mon Sep 17 00:00:00 2001 +From: Alex Marginean <alexandru.marginean@nxp.com> +Date: Wed, 15 Jan 2020 15:49:11 +0200 +Subject: [PATCH] drivers: net: dsa: felix: don't restart PCS SGMII AN if not + needed + +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. + +Suggested-by: Vladimir Oltean <vladimir.oltean@nxp.com> +Signed-off-by: Alex Marginean <alexandru.marginean@nxp.com> +--- + drivers/net/dsa/ocelot/felix_vsc9959.c | 15 +++++++++++++++ + 1 file changed, 15 insertions(+) + +--- a/drivers/net/dsa/ocelot/felix_vsc9959.c ++++ b/drivers/net/dsa/ocelot/felix_vsc9959.c +@@ -648,7 +648,22 @@ static void vsc9959_pcs_init_sgmii(struc + unsigned int link_an_mode, + const struct phylink_link_state *state) + { ++ int bmsr, bmcr; ++ + if (link_an_mode == MLO_AN_INBAND) { ++ /* 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); ++ bmsr = phy_read(pcs, MII_BMSR); ++ 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. + */ |