From d6db61a40ee056f0b067b924d28b276306474a9c Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Wed, 1 Feb 2017 20:19:25 +0100 Subject: [PATCH] net: stmmac: don't set tx delay in RGMII_ID and RGMII_TXID mode As documented in Documentation/devicetree/bindings/net/ethernet.txt, in RGMII_ID and RGMII_TXID mode the MAC should not add a tx delay. Signed-off-by: Heiner Kallweit Signed-off-by: David S. Miller --- drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c index 8840a36..9685555 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c @@ -177,12 +177,19 @@ static int meson8b_init_prg_eth(struct meson8b_dwmac *dwmac) { int ret; unsigned long clk_rate; - u8 tx_dly_val; + u8 tx_dly_val = 0; switch (dwmac->phy_mode) { case PHY_INTERFACE_MODE_RGMII: - case PHY_INTERFACE_MODE_RGMII_ID: case PHY_INTERFACE_MODE_RGMII_RXID: + /* TX clock delay in ns = "8ns / 4 * tx_dly_val" (where + * 8ns are exactly one cycle of the 125MHz RGMII TX clock): + * 0ns = 0x0, 2ns = 0x1, 4ns = 0x2, 6ns = 0x3 + */ + tx_dly_val = dwmac->tx_delay_ns >> 1; + /* fall through */ + + case PHY_INTERFACE_MODE_RGMII_ID: case PHY_INTERFACE_MODE_RGMII_TXID: /* Generate a 25MHz clock for the PHY */ clk_rate = 25 * 1000 * 1000; @@ -195,11 +202,6 @@ static int meson8b_init_prg_eth(struct meson8b_dwmac *dwmac) meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_INVERTED_RMII_CLK, 0); - /* TX clock delay in ns = "8ns / 4 * tx_dly_val" (where - * 8ns are exactly one cycle of the 125MHz RGMII TX clock): - * 0ns = 0x0, 2ns = 0x1, 4ns = 0x2, 6ns = 0x3 - */ - tx_dly_val = dwmac->tx_delay_ns >> 1; meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TXDLY_MASK, tx_dly_val << PRG_ETH0_TXDLY_SHIFT); break; -- 2.7.4