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>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 4b501b48ce86..53563d53b5ad 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -1383,4 +1383,13 @@ static inline int ieee80211_freq_to_ofdm_chan(int s_freq, int freq)
                 return -1;
 }
 
+/**
+ * ieee80211_tu_to_usec - convert time units (TU) to microseconds
+ * @tu: the TUs
+ */
+static inline unsigned long ieee80211_tu_to_usec(unsigned long tu)
+{
+        return 1024 * tu;
+}
+
 #endif /* LINUX_IEEE80211_H */