Re: [patch net-next v5 3/8] switchdev: allow caller to explicitly request attr_set as deferred

From: Jiri Pirko <redacted>

Caller should know if he can call attr_set directly (when holding RTNL)
or if he has to defer the att_set processing for later.

This also allows drivers to sleep inside attr_set and report operation
status back to switchdev core. Switchdev core then warns if status is
not ok, instead of silent errors happening in drivers.

Benefit from newly introduced switchdev deferred ops infrastructure.

Signed-off-by: Jiri Pirko <redacted>
---
 include/net/switchdev.h   |   1 +
 net/bridge/br_stp.c       |   3 +-
 net/switchdev/switchdev.c | 108 ++++++++++++++++++----------------------------
 3 files changed, 46 insertions(+), 66 deletions(-)

diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index d1c7f90..f7de6f8 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h

@@ -17,6 +17,7 @@

 #define SWITCHDEV_F_NO_RECURSE         BIT(0)
 #define SWITCHDEV_F_SKIP_EOPNOTSUPP    BIT(1)
+#define SWITCHDEV_F_DEFER              BIT(2)

 struct switchdev_trans_item {
        struct list_head list;

diff --git a/net/bridge/br_stp.c b/net/bridge/br_stp.c
index db6d243de..80c34d7 100644
--- a/net/bridge/br_stp.c
+++ b/net/bridge/br_stp.c

@@ -41,13 +41,14 @@ void br_set_state(struct net_bridge_port *p, unsigned int state)
 {
        struct switchdev_attr attr = {
                .id = SWITCHDEV_ATTR_ID_PORT_STP_STATE,
+               .flags = SWITCHDEV_F_DEFER,
                .u.stp_state = state,
        };
        int err;

        p->state = state;
        err = switchdev_port_attr_set(p->dev, &attr);
-       if (err && err != -EOPNOTSUPP)
+       if (err)
                br_warn(p->br, "error setting offload STP state on port %u(%s)\n",
                                (unsigned int) p->port_no, p->dev->name);
 }