The Qualcomm board always chooses the MAC to provide the delay instead of
the PHY, which is completely opposite to the suggestion of the Linux
kernel. The usage of phy-mode in legacy DTS was also incorrect. Change the
phy_mode passed from the DTS to the driver from PHY_INTERFACE_MODE_RGMII_ID
to PHY_INTERFACE_MODE_RGMII to ensure correct operation and adherence to
the definition.
To address the ABI compatibility issue between the kernel and DTS caused by
this change, handle the compatible string 'qcom,qcs404-evb-4000' in the
code, as it is the only legacy board that mistakenly uses the 'rgmii'
phy-mode.

Signed-off-by: Yijie Yang <redacted>
---
 .../net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c    | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
index 2a5b38723635b5ef9233ca4709e99dd5ddf06b77..e228a62723e221d58d8c4f104109e0dcf682d06d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c

@@ -401,14 +401,11 @@ static int ethqos_dll_configure(struct qcom_ethqos *ethqos)
 static int ethqos_rgmii_macro_init(struct qcom_ethqos *ethqos)
 {
 	struct device *dev = &ethqos->pdev->dev;
-	int phase_shift;
+	int phase_shift = 0;
 	int loopback;
 
 	/* Determine if the PHY adds a 2 ns TX delay or the MAC handles it */
-	if (ethqos->phy_mode == PHY_INTERFACE_MODE_RGMII_ID ||
-	    ethqos->phy_mode == PHY_INTERFACE_MODE_RGMII_TXID)
-		phase_shift = 0;
-	else
+	if (ethqos->phy_mode == PHY_INTERFACE_MODE_RGMII_ID)
 		phase_shift = RGMII_CONFIG2_TX_CLK_PHASE_SHIFT_EN;