mac80211: disable powersave if pm_qos asks for low latency
When an application asks for a latency lower than the beacon interval
there's nothing we can do -- we need to stay awake and not have the
AP buffer frames for us. Add code to automatically calculate this
constraint in mac80211 so drivers need not concern themselves with it.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 06d9a1d..c39a214 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -17,6 +17,7 @@
#include <linux/if_arp.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
+#include <linux/pm_qos_params.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>
@@ -515,7 +516,7 @@
}
/* need to hold RTNL or interface lock */
-void ieee80211_recalc_ps(struct ieee80211_local *local)
+void ieee80211_recalc_ps(struct ieee80211_local *local, s32 latency)
{
struct ieee80211_sub_if_data *sdata, *found = NULL;
int count = 0;
@@ -534,10 +535,22 @@
count++;
}
- if (count == 1 && found->u.mgd.powersave)
- local->ps_sdata = found;
- else
+ if (count == 1 && found->u.mgd.powersave) {
+ s32 beaconint_us;
+
+ if (latency < 0)
+ latency = pm_qos_requirement(PM_QOS_NETWORK_LATENCY);
+
+ beaconint_us = ieee80211_tu_to_usec(
+ found->vif.bss_conf.beacon_int);
+
+ if (beaconint_us > latency)
+ local->ps_sdata = NULL;
+ else
+ local->ps_sdata = found;
+ } else {
local->ps_sdata = NULL;
+ }
ieee80211_change_ps(local);
}
@@ -2324,3 +2337,18 @@
ieee80211_restart_sta_timer(sdata);
rcu_read_unlock();
}
+
+int ieee80211_max_network_latency(struct notifier_block *nb,
+ unsigned long data, void *dummy)
+{
+ s32 latency_usec = (s32) data;
+ struct ieee80211_local *local =
+ container_of(nb, struct ieee80211_local,
+ network_latency_notifier);
+
+ mutex_lock(&local->iflist_mtx);
+ ieee80211_recalc_ps(local, latency_usec);
+ mutex_unlock(&local->iflist_mtx);
+
+ return 0;
+}