[PATCH 5.5 40/65] net: bcmgenet: Clear ID_MODE_DIS in EXT_RGMII_OOB_CTRL when not needed

[Greg Kroah-Hartman]

From: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>

[ Upstream commit 402482a6a78e5c61d8a2ec6311fc5b4aca392cd6 ]

Outdated Raspberry Pi 4 firmware might configure the external PHY as
rgmii although the kernel currently sets it as rgmii-rxid. This makes
connections unreliable as ID_MODE_DIS is left enabled. To avoid this,
explicitly clear that bit whenever we don't need it.

Fixes: da38802211cc ("net: bcmgenet: Add RGMII_RXID support")
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
Acked-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/broadcom/genet/bcmmii.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
index 6392a25301838..10244941a7a60 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
@@ -294,6 +294,7 @@ int bcmgenet_mii_config(struct net_device *dev, bool init)
 	 */
 	if (priv->ext_phy) {
 		reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
+		reg &= ~ID_MODE_DIS;
 		reg |= id_mode_dis;
 		if (GENET_IS_V1(priv) || GENET_IS_V2(priv) || GENET_IS_V3(priv))
 			reg |= RGMII_MODE_EN_V123;
-- 
2.20.1