Re: [PATCH 5.10 041/290] net: enetc: force the RGMII speed and duplex instead of operating in inband mode

From: Pavel Machek
Date: Thu Mar 18 2021 - 08:35:37 EST


Hi!

> It has been reported that RGMII is broken in fixed-link, and that is not
> surprising considering the fact that no PHY is attached to the MAC in
> that case, but a switch.

Okay, but there's something wrong in the code.

> This brings us to the topic of the patch: the enetc driver should have
> not enabled the optional in-band status signaling for RGMII unconditionally,
> but should have forced the speed and duplex to what was resolved by
> phylink.

> +++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
> @@ -494,13 +494,20 @@ static void enetc_configure_port_mac(str
>
> static void enetc_mac_config(struct enetc_hw *hw, phy_interface_t phy_mode)
> {
...
> + u32 val;
> +
> + if (phy_interface_mode_is_rgmii(phy_mode)) {
> + val = enetc_port_rd(hw, ENETC_PM0_IF_MODE);
> + val &= ~ENETC_PM0_IFM_EN_AUTO;
> + val &= ENETC_PM0_IFM_IFMODE_MASK;
> + val |= ENETC_PM0_IFM_IFMODE_GMII | ENETC_PM0_IFM_RG;
> + enetc_port_wr(hw, ENETC_PM0_IF_MODE, val);
> + }

val clears ENETC_PM0_IFM_EN_AUTO bit, then the bit is cleared again,
preserving just IFMODE bits, then ors the IFMODE bits with new values.

I believe this is needed:

Signed-off-by: Pavel Machek (CIP) <pavel@xxxxxxx>
Pavel

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.c b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
index 83187cd59fdd..446ad4c43fab 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_pf.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
@@ -499,7 +499,7 @@ static void enetc_mac_config(struct enetc_hw *hw, phy_interface_t phy_mode)
if (phy_interface_mode_is_rgmii(phy_mode)) {
val = enetc_port_rd(hw, ENETC_PM0_IF_MODE);
val &= ~ENETC_PM0_IFM_EN_AUTO;
- val &= ENETC_PM0_IFM_IFMODE_MASK;
+ val &= ~ENETC_PM0_IFM_IFMODE_MASK;
val |= ENETC_PM0_IFM_IFMODE_GMII | ENETC_PM0_IFM_RG;
enetc_port_wr(hw, ENETC_PM0_IF_MODE, val);
}


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