[PATCH 4.19 151/421] net: bcmgenet: Fix attaching to PYH failed on RPi 4B

From: Greg Kroah-Hartman
Date: Mon Jul 19 2021 - 12:17:52 EST

From: Jian-Hong Pan <jhp@xxxxxxxxxxxxx>

[ Upstream commit b2ac9800cfe0f8da16abc4e74e003440361c112e ]

The Broadcom UniMAC MDIO bus from mdio-bcm-unimac module comes too late.
So, GENET cannot find the ethernet PHY on UniMAC MDIO bus. This leads
GENET fail to attach the PHY as following log:

bcmgenet fd580000.ethernet: GENET 5.0 EPHY: 0x0000
could not attach to PHY
bcmgenet fd580000.ethernet eth0: failed to connect to PHY
uart-pl011 fe201000.serial: no DMA platform data
libphy: bcmgenet MII bus: probed
unimac-mdio unimac-mdio.-19: Broadcom UniMAC MDIO bus

This patch adds the soft dependency to load mdio-bcm-unimac module
before genet module to avoid the issue.

Fixes: 9a4e79697009 ("net: bcmgenet: utilize generic Broadcom UniMAC MDIO controller driver")
Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=213485
Signed-off-by: Jian-Hong Pan <jhp@xxxxxxxxxxxxx>
Signed-off-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/bcmgenet.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index c3e824f5e50e..1546a9bd9203 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -3750,3 +3750,4 @@ MODULE_AUTHOR("Broadcom Corporation");
MODULE_DESCRIPTION("Broadcom GENET Ethernet controller driver");
+MODULE_SOFTDEP("pre: mdio-bcm-unimac");