Re: [PATCH] net: dsa: mt7530: fix null pointer dereferencing in port5 setup

[Vivien Didelot]

On Fri,  3 Apr 2020 19:28:24 +0800, Chuanhong Guo <gch981213@xxxxxxxxx> wrote:
> 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@xxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx

Reviewed-by: Vivien Didelot <vivien.didelot@xxxxxxxxx>