net: bcmgenet: Fix attaching to PYH failed on RPi 4B

BugLink: https://bugs.launchpad.net/bugs/1938199
[ 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@endlessos.org>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index b27da024aa9d99f7200403337b94ee2540086c01..21669a42718c8067a9e6ee8d74746db414a2feeb 100644 (file)
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -3741,3 +3741,4 @@ MODULE_AUTHOR("Broadcom Corporation");
 MODULE_DESCRIPTION("Broadcom GENET Ethernet controller driver");
 MODULE_ALIAS("platform:bcmgenet");
 MODULE_LICENSE("GPL");
+MODULE_SOFTDEP("pre: mdio-bcm-unimac");