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authorVladimir Oltean <vladimir.oltean@nxp.com>2021-09-17 17:29:16 +0300
committerDavid S. Miller <davem@davemloft.net>2021-09-19 15:05:44 +0300
commitfd292c189a979838622d5e03e15fa688c81dd50b (patch)
tree31ccbaf0e70b4468bcd5560371b7f4e9481b1d3d /include
parentfdb475838539cb516caeeeaed06b4b5bc62c9179 (diff)
downloadlinux-fd292c189a979838622d5e03e15fa688c81dd50b.tar.xz
net: dsa: tear down devlink port regions when tearing down the devlink port on error
Commit 86f8b1c01a0a ("net: dsa: Do not make user port errors fatal") decided it was fine to ignore errors on certain ports that fail to probe, and go on with the ports that do probe fine. Commit fb6ec87f7229 ("net: dsa: Fix type was not set for devlink port") noticed that devlink_port_type_eth_set(dlp, dp->slave); does not get called, and devlink notices after a timeout of 3600 seconds and prints a WARN_ON. So it went ahead to unregister the devlink port. And because there exists an UNUSED port flavour, we actually re-register the devlink port as UNUSED. Commit 08156ba430b4 ("net: dsa: Add devlink port regions support to DSA") added devlink port regions, which are set up by the driver and not by DSA. When we trigger the devlink port deregistration and reregistration as unused, devlink now prints another WARN_ON, from here: devlink_port_unregister: WARN_ON(!list_empty(&devlink_port->region_list)); So the port still has regions, which makes sense, because they were set up by the driver, and the driver doesn't know we're unregistering the devlink port. Somebody needs to tear them down, and optionally (actually it would be nice, to be consistent) set them up again for the new devlink port. But DSA's layering stays in our way quite badly here. The options I've considered are: 1. Introduce a function in devlink to just change a port's type and flavour. No dice, devlink keeps a lot of state, it really wants the port to not be registered when you set its parameters, so changing anything can only be done by destroying what we currently have and recreating it. 2. Make DSA cache the parameters passed to dsa_devlink_port_region_create, and the region returned, keep those in a list, then when the devlink port unregister needs to take place, the existing devlink regions are destroyed by DSA, and we replay the creation of new regions using the cached parameters. Problem: mv88e6xxx keeps the region pointers in chip->ports[port].region, and these will remain stale after DSA frees them. There are many things DSA can do, but updating mv88e6xxx's private pointers is not one of them. 3. Just let the driver do it (i.e. introduce a very specific method called ds->ops->port_reinit_as_unused, which unregisters its devlink port devlink regions, then the old devlink port, then registers the new one, then the devlink port regions for it). While it does work, as opposed to the others, it's pretty horrible from an API perspective and we can do better. 4. Introduce a new pair of methods, ->port_setup and ->port_teardown, which in the case of mv88e6xxx must register and unregister the devlink port regions. Call these 2 methods when the port must be reinitialized as unused. Naturally, I went for the 4th approach. Fixes: 08156ba430b4 ("net: dsa: Add devlink port regions support to DSA") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r--include/net/dsa.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/include/net/dsa.h b/include/net/dsa.h
index 6e29c0e080f6..d784e76113b8 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -585,8 +585,16 @@ struct dsa_switch_ops {
int (*change_tag_protocol)(struct dsa_switch *ds, int port,
enum dsa_tag_protocol proto);
+ /* Optional switch-wide initialization and destruction methods */
int (*setup)(struct dsa_switch *ds);
void (*teardown)(struct dsa_switch *ds);
+
+ /* Per-port initialization and destruction methods. Mandatory if the
+ * driver registers devlink port regions, optional otherwise.
+ */
+ int (*port_setup)(struct dsa_switch *ds, int port);
+ void (*port_teardown)(struct dsa_switch *ds, int port);
+
u32 (*get_phy_flags)(struct dsa_switch *ds, int port);
/*