net: dsa: Fix load order between DSA drivers and taggers

The DSA core, DSA taggers and DSA drivers all make use of
module_init(). Hence they get initialised at device_initcall() time.
The ordering is non-deterministic. It can be a DSA driver is bound to
a device before the needed tag driver has been initialised, resulting
in the message:

No tagger for this switch

Rather than have this be fatal, return -EPROBE_DEFER so that it is
tried again later once all the needed drivers have been loaded.

Fixes: d3b8c04988 ("dsa: Add boilerplate helper to register DSA tag driver modules")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Andrew Lunn 2019-09-12 15:16:45 +02:00 committed by David S. Miller
parent d518d2ed86
commit 23426a25e5

View File

@ -623,6 +623,8 @@ static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master)
tag_protocol = ds->ops->get_tag_protocol(ds, dp->index);
tag_ops = dsa_tag_driver_get(tag_protocol);
if (IS_ERR(tag_ops)) {
if (PTR_ERR(tag_ops) == -ENOPROTOOPT)
return -EPROBE_DEFER;
dev_warn(ds->dev, "No tagger for this switch\n");
return PTR_ERR(tag_ops);
}