Re: [PATCH net-next 1/6] net: dsa: assert uniqueness of dsa,member properties

On Fri, Jun 18, 2021 at 09:30:12PM +0300, Vladimir Oltean wrote:

From: Vladimir Oltean <vladimir.oltean@nxp.com>

The cross-chip notifiers work by comparing each ds->index against the
info->sw_index value from the notifier. The ds->index is retrieved from
the device tree dsa,member property.

If a single tree cross-chip topology does not declare unique switch IDs,
this will result in hard-to-debug issues/voodoo effects such as the
cross-chip notifier for one switch port also matching the port with the
same number from another switch.

Check in dsa_switch_parse_member_of() whether the DSA switch tree
contains a DSA switch with the index we're preparing to add, before
actually adding it.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew