mac80211: reply only once to each PS-poll

If a PS-poll frame is retried (but was received)
there is no way to detect that since it has no
sequence number. As a consequence, the standard
asks us to not react to PS-poll frames until the
response to one made it out (was ACKed or lost).

Implement this by using the WLAN_STA_SP flags to
also indicate a PS-Poll "service period" and the
IEEE80211_TX_STATUS_EOSP flag for the response
packet to indicate the end of the "SP" as usual.

We could use separate flags, but that will most
likely completely confuse drivers, and while the
standard doesn't exclude simultaneously polling
using uAPSD and PS-Poll, doing that seems quite
problematic.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 751ad25f925f..348847a32630 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -50,7 +50,7 @@
  *      keeping station in power-save mode, reply when the driver
  *      unblocks the station.
  * @WLAN_STA_SP: Station is in a service period, so don't try to
- *      reply to other uAPSD trigger frames.
+ *      reply to other uAPSD trigger frames or PS-Poll.
  */
 enum ieee80211_sta_info_flags {
         WLAN_STA_AUTH           = 1<<0,