Create a new task to handle 802.11n channel width changes.

Currently, a channel width change updates the 802.11n HT info data in
net80211 but it doesn't trigger any device changes.  So the device
driver may decide that HT40 frames can be transmitted but the last
device channel set only had HT20 set.

Now, a task is scheduled so a hardware reset or change isn't done
during any active ongoing RX. It also means that it's serialised
with the other task operations (eg channel change.)

This isn't the final incantation of this work, see below.

For now, any unmodified drivers will simply receive a channel
change log entry.  A subsequent patch to ath(4) will introduce
some basic channel change handling (by resetting the NIC.)
Other NICs may need to update their rate control information.

TODO:

* There's still a small window at the present moment where the
  channel width has been updated but the task hasn't been fired.
  The final version of this should likely pass in a channel width
  field to the driver and let the driver atomically do whatever
  it needs to before changing the channel.

PR:		kern/166286

1 files changed, 8 insertions, 0 deletions

diff --git a/sys/net80211/ieee80211_node.c b/sys/net80211/ieee80211_node.c
index 71f97f0..861fa85 100644
--- a/sys/net80211/ieee80211_node.c
+++ b/sys/net80211/ieee80211_node.c
@@ -685,6 +685,14 @@ ieee80211_setcurchan(struct ieee80211com *ic, struct ieee80211_channel *c)
 	ieee80211_runtask(ic, &ic->ic_chan_task);
 }
 
+void
+ieee80211_update_chw(struct ieee80211com *ic)
+{
+
+	ieee80211_setupcurchan(ic, ic->ic_curchan);
+	ieee80211_runtask(ic, &ic->ic_chw_task);
+}
+
 /*
  * Join the specified IBSS/BSS network.  The node is assumed to
  * be passed in with a held reference.