psp: add a comment about a psp_dev add netlink notification

In psp_dev_create(), the DEV_ADD_NTF netlink notification is sent
before the device is published to the netdev via rcu_assign_pointer().
IIRC this is intentional because a single PSP device is expected
to be shared with multiple netdevs. So we are trying to default to
not having the netdev info. We can change it if someone complains
but for now just add a comment that it's intentional.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260428205352.1247325-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/psp/psp_main.c b/net/psp/psp_main.c
index 652ec8a9c8a49cbe871749f22f14cb489830f66a..f069117c867ae9182731af83ea7ec4378f6169ec 100644 (file)
--- a/net/psp/psp_main.c
+++ b/net/psp/psp_main.c
@@ -90,6 +90,10 @@ psp_dev_create(struct net_device *netdev,
        mutex_lock(&psd->lock);
        mutex_unlock(&psp_devs_lock);
 
+       /* notify before netdev assignment
+        * There's no strong reason for it, but thinking is to avoid creating
+        * implicit expectations about the PSP dev <> netdev relationship.
+        */
        psp_nl_notify_dev(psd, PSP_CMD_DEV_ADD_NTF);
 
        rcu_assign_pointer(netdev->psp_dev, psd);