diff options
Diffstat (limited to 'target/linux/generic/backport-5.15/766-v5.18-02-net-dsa-replay-master-state-events-in-dsa_tree_-setu.patch')
| -rw-r--r-- | target/linux/generic/backport-5.15/766-v5.18-02-net-dsa-replay-master-state-events-in-dsa_tree_-setu.patch | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/target/linux/generic/backport-5.15/766-v5.18-02-net-dsa-replay-master-state-events-in-dsa_tree_-setu.patch b/target/linux/generic/backport-5.15/766-v5.18-02-net-dsa-replay-master-state-events-in-dsa_tree_-setu.patch new file mode 100644 index 0000000000..6478d580c0 --- /dev/null +++ b/target/linux/generic/backport-5.15/766-v5.18-02-net-dsa-replay-master-state-events-in-dsa_tree_-setu.patch @@ -0,0 +1,89 @@ +From e83d56537859849f2223b90749e554831b1f3c27 Mon Sep 17 00:00:00 2001 +From: Vladimir Oltean <vladimir.oltean@nxp.com> +Date: Wed, 2 Feb 2022 01:03:21 +0100 +Subject: [PATCH 02/16] net: dsa: replay master state events in + dsa_tree_{setup,teardown}_master + +In order for switch driver to be able to make simple and reliable use of +the master tracking operations, they must also be notified of the +initial state of the DSA master, not just of the changes. This is +because they might enable certain features only during the time when +they know that the DSA master is up and running. + +Therefore, this change explicitly checks the state of the DSA master +under the same rtnl_mutex as we were holding during the +dsa_master_setup() and dsa_master_teardown() call. The idea being that +if the DSA master became operational in between the moment in which it +became a DSA master (dsa_master_setup set dev->dsa_ptr) and the moment +when we checked for the master being up, there is a chance that we +would emit a ->master_state_change() call with no actual state change. +We need to avoid that by serializing the concurrent netdevice event with +us. If the netdevice event started before, we force it to finish before +we begin, because we take rtnl_lock before making netdev_uses_dsa() +return true. So we also handle that early event and do nothing on it. +Similarly, if the dev_open() attempt is concurrent with us, it will +attempt to take the rtnl_mutex, but we're holding it. We'll see that +the master flag IFF_UP isn't set, then when we release the rtnl_mutex +we'll process the NETDEV_UP notifier. + +Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> +Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com> +Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> +Signed-off-by: David S. Miller <davem@davemloft.net> +--- + net/dsa/dsa2.c | 28 ++++++++++++++++++++++++---- + 1 file changed, 24 insertions(+), 4 deletions(-) + +--- a/net/dsa/dsa2.c ++++ b/net/dsa/dsa2.c +@@ -15,6 +15,7 @@ + #include <linux/of.h> + #include <linux/of_net.h> + #include <net/devlink.h> ++#include <net/sch_generic.h> + + #include "dsa_priv.h" + +@@ -1060,9 +1061,18 @@ static int dsa_tree_setup_master(struct + + list_for_each_entry(dp, &dst->ports, list) { + if (dsa_port_is_cpu(dp)) { +- err = dsa_master_setup(dp->master, dp); ++ struct net_device *master = dp->master; ++ bool admin_up = (master->flags & IFF_UP) && ++ !qdisc_tx_is_noop(master); ++ ++ err = dsa_master_setup(master, dp); + if (err) + return err; ++ ++ /* Replay master state event */ ++ dsa_tree_master_admin_state_change(dst, master, admin_up); ++ dsa_tree_master_oper_state_change(dst, master, ++ netif_oper_up(master)); + } + } + +@@ -1077,9 +1087,19 @@ static void dsa_tree_teardown_master(str + + rtnl_lock(); + +- list_for_each_entry(dp, &dst->ports, list) +- if (dsa_port_is_cpu(dp)) +- dsa_master_teardown(dp->master); ++ list_for_each_entry(dp, &dst->ports, list) { ++ if (dsa_port_is_cpu(dp)) { ++ struct net_device *master = dp->master; ++ ++ /* Synthesizing an "admin down" state is sufficient for ++ * the switches to get a notification if the master is ++ * currently up and running. ++ */ ++ dsa_tree_master_admin_state_change(dst, master, false); ++ ++ dsa_master_teardown(master); ++ } ++ } + + rtnl_unlock(); + } |