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: d3b8c04988ca ("dsa: Add boilerplate helper to register DSA tag driver
modules")
Signed-off-by: Andrew Lunn <and...@lunn.ch>
---
I did wonder if we should play with the core and tag drivers and make
them use subsystem_initcall(), but EPROBE_DEFER seems to be the more
preferred solution nowadays.
---
net/dsa/dsa2.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 3abd173ebacb..96f787cf9b6e 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -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);
}
--
2.23.0
