From: Daniel Golle <daniel@xxxxxxxxxxxxxx> [ Upstream commit 611e2dabb4b3243d176739fd6a5a34d007fa3f86 ] Reset the internal PCS state machine when changing interface mode. This prevents confusing the state machine when changing interface modes, e.g. from SGMII to 2500Base-X or vice-versa. Fixes: 7e538372694b ("net: ethernet: mediatek: Re-add support SGMII") Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Tested-by: Bjørn Mork <bjorn@xxxxxxx> Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/ethernet/mediatek/mtk_eth_soc.h | 4 ++++ drivers/net/ethernet/mediatek/mtk_sgmii.c | 4 ++++ 2 files changed, 8 insertions(+) diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h index b481d0d46bb16..d4b4f9eaa4419 100644 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h @@ -528,6 +528,10 @@ #define SGMII_SEND_AN_ERROR_EN BIT(11) #define SGMII_IF_MODE_MASK GENMASK(5, 1) +/* Register to reset SGMII design */ +#define SGMII_RESERVED_0 0x34 +#define SGMII_SW_RESET BIT(0) + /* Register to set SGMII speed, ANA RG_ Control Signals III*/ #define SGMSYS_ANA_RG_CS3 0x2028 #define RG_PHY_SPEED_MASK (BIT(2) | BIT(3)) diff --git a/drivers/net/ethernet/mediatek/mtk_sgmii.c b/drivers/net/ethernet/mediatek/mtk_sgmii.c index bb00de1003ac4..612f65bb03454 100644 --- a/drivers/net/ethernet/mediatek/mtk_sgmii.c +++ b/drivers/net/ethernet/mediatek/mtk_sgmii.c @@ -88,6 +88,10 @@ static int mtk_pcs_config(struct phylink_pcs *pcs, unsigned int mode, regmap_update_bits(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL, SGMII_PHYA_PWD, SGMII_PHYA_PWD); + /* Reset SGMII PCS state */ + regmap_update_bits(mpcs->regmap, SGMII_RESERVED_0, + SGMII_SW_RESET, SGMII_SW_RESET); + if (interface == PHY_INTERFACE_MODE_2500BASEX) rgc3 = RG_PHY_SPEED_3_125G; else -- 2.39.2