We should disable tx/rx delay in rgmii mode, but driver doesn't do so. Hence add a device tree property to avoid breaking current users and disable only when this property is set
<Fixme: change author to ...> Signed-off-by: Vinod Koul <vk...@kernel.org> --- drivers/net/dsa/qca8k.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c index 7e97e620bd44..6dfb390ebe66 100644 --- a/drivers/net/dsa/qca8k.c +++ b/drivers/net/dsa/qca8k.c @@ -420,7 +420,9 @@ qca8k_mib_init(struct qca8k_priv *priv) static int qca8k_set_pad_ctrl(struct qca8k_priv *priv, int port, int mode) { - u32 reg; + u32 reg, val; + struct dsa_switch *ds = priv->ds; + bool rx_delay_disable, tx_delay_disable; switch (port) { case 0: @@ -439,17 +441,24 @@ qca8k_set_pad_ctrl(struct qca8k_priv *priv, int port, int mode) */ switch (mode) { case PHY_INTERFACE_MODE_RGMII: - qca8k_write(priv, reg, - QCA8K_PORT_PAD_RGMII_EN | - QCA8K_PORT_PAD_RGMII_TX_DELAY(3) | - QCA8K_PORT_PAD_RGMII_RX_DELAY(3)); - - /* According to the datasheet, RGMII delay is enabled through + rx_delay_disable = of_property_read_bool(ds->dst->cpu_dp->dn, + "rx-delay-disable"); + tx_delay_disable = of_property_read_bool(ds->dst->cpu_dp->dn, + "tx-delay-disable"); + val = QCA8K_PORT_PAD_RGMII_EN; + if (!rx_delay_disable) + val |= QCA8K_PORT_PAD_RGMII_RX_DELAY(3); + if (!tx_delay_disable) + val |= QCA8K_PORT_PAD_RGMII_TX_DELAY(3); + qca8k_write(priv, reg, val); + + /* According to the datasheet, RGMII rx delay is enabled through * PORT5_PAD_CTRL for all ports, rather than individual port * registers */ - qca8k_write(priv, QCA8K_REG_PORT5_PAD_CTRL, - QCA8K_PORT_PAD_RGMII_RX_DELAY_EN); + if (!rx_delay_disable) + qca8k_write(priv, QCA8K_REG_PORT5_PAD_CTRL, + QCA8K_PORT_PAD_RGMII_RX_DELAY_EN); break; case PHY_INTERFACE_MODE_SGMII: qca8k_write(priv, reg, QCA8K_PORT_PAD_SGMII_EN); -- 2.20.1