The 2nd gmac of mediatek soc ethernet may not be connected to a PHY and a phy-handle isn't always available. Unfortunately, mt7530 dsa driver assumes that the 2nd gmac is always connected to switch port 5 and setup mt7530 according to phy address of 2nd gmac node, causing null pointer dereferencing when phy-handle isn't defined in dts. This commit fix this setup code by checking return value of of_parse_phandle before using it.
Fixes: 38f790a80560 ("net: dsa: mt7530: Add support for port 5") Signed-off-by: Chuanhong Guo gch981213@gmail.com Cc: stable@vger.kernel.org ---
mt7530 is available as a standalone chip and we should not make it tightly coupled with a specific type of ethernet dt binding in the first place. A proper fix is to replace this port detection logic with a dt property under mt7530 node, but that's too much for linux-stable.
drivers/net/dsa/mt7530.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c index 6e91fe2f4b9a..1d53a4ebcd5a 100644 --- a/drivers/net/dsa/mt7530.c +++ b/drivers/net/dsa/mt7530.c @@ -1414,6 +1414,9 @@ mt7530_setup(struct dsa_switch *ds) continue;
phy_node = of_parse_phandle(mac_np, "phy-handle", 0); + if (!phy_node) + continue; + if (phy_node->parent == priv->dev->of_node->parent) { ret = of_get_phy_mode(mac_np, &interface); if (ret && ret != -ENODEV)