On Sat, Apr 04, 2020 at 11:19:10AM +0800, Chuanhong Guo wrote:
Hi!
On Sat, Apr 4, 2020 at 2:09 AM René van Dorst opensource@vdorst.com wrote:
Quoting Chuanhong Guo gch981213@gmail.com:
Hi Chuanhong,
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.
MT7530 tries to detect if 2nd GMAC is using a phy with phy-address 0 or 4.
What if the 2nd GMAC connects to an external PHY on address 0 on a different mdio-bus?
In general, you using a phy-handle to cover such a situation. If there is a phy-handle, just use it.
Andrew