[PATCH] net: ti: am65-cpsw-nuss: Don't crash in am65_cpsw_phy_init()

[A. Sverdlin]

From: Alexander Sverdlin <alexander.sverdlin at siemens.com>

am65_cpsw_ofdata_parse_phy() tries to handle the case when PHY is not
specified in DT gracefully:

am65_cpsw_nuss_port ethernet at 8000000port@1: can't parse phy-handle port 1 (-2)

am65_cpsw_mdio_init() is turn is prepared for this, checks
if priv->has_phy == 0 and bails out (leaving cpsw_common->bus == NULL).

am65_cpsw_phy_init() however is not prepared for this and calls
phy_connect(cpsw_common->bus, ...) unconditionally, which leads to:

"Synchronous Abort" handler, esr 0x8600000d, far 0x0
elr: ffffffff808ab000 lr : 000000008083bde4 (reloc)

where lr points to the instruction right after bus->read() in get_phy_id().

Fixes: 9d0dca1199d1 ("net: ethernet: ti: Introduce am654 gigabit eth switch subsystem driver")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin at siemens.com>
---
 drivers/net/ti/am65-cpsw-nuss.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ti/am65-cpsw-nuss.c b/drivers/net/ti/am65-cpsw-nuss.c
index 6da018c0f9d5..d1e452b6b43c 100644
--- a/drivers/net/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ti/am65-cpsw-nuss.c
@@ -722,6 +722,9 @@ static int am65_cpsw_phy_init(struct udevice *dev)
 	u32 supported = PHY_GBIT_FEATURES;
 	int ret;
 
+	if (!priv->has_phy || !cpsw_common->bus)
+		return 0;
+
 	phydev = phy_connect(cpsw_common->bus,
 			     priv->phy_addr,
 			     priv->dev,
-- 
2.44.0