iwlwifi: handle unicast PS buffering

Using the new mac80211 functionality, this makes
iwlwifi handle unicast PS buffering correctly.
The device works like this:

 * when a station goes to sleep, the microcode notices
   this and marks the station as asleep
 * when the station is marked asleep, the microcode
   refuses to transmit to the station and rejects all
   frames queued to it with the failure status code
   TX_STATUS_FAIL_DEST_PS (a previous patch handled
   this correctly)
 * when we need to send frames to the station _although_
   it is asleep, we need to tell the ucode how many,
   and this is asynchronous with sending so we cannot
   just send the frames, we need to wait for all other
   frames to be flushed, and then update the counter
   before sending out the poll response frames. This
   is handled partially in the driver and partially in
   mac80211.

In order to do all this correctly, we need to
 * keep track of how many frames are pending for each
   associated client station (avoid doing it for other
   stations to avoid the atomic ops)
 * tell mac80211 that we driver-block the PS status
   while there are still frames pending on the queues,
   and once they are all rejected (due to the dest sta
   being in PS) unblock mac80211

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 3 insertions, 7 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h
index a474383ec0b..f1601cfebc2 100644
--- a/drivers/net/wireless/iwlwifi/iwl-dev.h
+++ b/drivers/net/wireless/iwlwifi/iwl-dev.h
@@ -545,15 +545,11 @@ struct iwl_qos_info {
 	struct iwl_qosparam_cmd def_qos_parm;
 };
 
-#define STA_PS_STATUS_WAKE             0
-#define STA_PS_STATUS_SLEEP            1
-
 
 struct iwl3945_station_entry {
 	struct iwl3945_addsta_cmd sta;
 	struct iwl_tid_data tid[MAX_TID_COUNT];
 	u8 used;
-	u8 ps_status;
 	struct iwl_hw_key keyinfo;
 };
 
@@ -561,7 +557,6 @@ struct iwl_station_entry {
 	struct iwl_addsta_cmd sta;
 	struct iwl_tid_data tid[MAX_TID_COUNT];
 	u8 used;
-	u8 ps_status;
 	struct iwl_hw_key keyinfo;
 };
 
@@ -571,11 +566,12 @@ struct iwl_station_entry {
  * When mac80211 creates a station it reserves some space (hw->sta_data_size)
  * in the structure for use by driver. This structure is places in that
  * space.
- *
- * At the moment use it for the station's rate scaling information.
  */
 struct iwl_station_priv {
 	struct iwl_lq_sta lq_sta;
+	atomic_t pending_frames;
+	bool client;
+	bool asleep;
 };
 
 /* one for each uCode image (inst/data, boot/init/runtime) */