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>
diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c
index 9370e06..ebfc460 100644
--- a/drivers/net/wireless/iwlwifi/iwl-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
@@ -709,6 +709,8 @@
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+ struct ieee80211_sta *sta = info->control.sta;
+ struct iwl_station_priv *sta_priv = NULL;
struct iwl_tx_queue *txq;
struct iwl_queue *q;
struct iwl_device_cmd *out_cmd;
@@ -771,6 +773,24 @@
IWL_DEBUG_TX(priv, "station Id %d\n", sta_id);
+ if (sta)
+ sta_priv = (void *)sta->drv_priv;
+
+ if (sta_priv && sta_id != priv->hw_params.bcast_sta_id &&
+ sta_priv->asleep) {
+ WARN_ON(!(info->flags & IEEE80211_TX_CTL_PSPOLL_RESPONSE));
+ /*
+ * This sends an asynchronous command to the device,
+ * but we can rely on it being processed before the
+ * next frame is processed -- and the next frame to
+ * this station is the one that will consume this
+ * counter.
+ * For now set the counter to just 1 since we do not
+ * support uAPSD yet.
+ */
+ iwl_sta_modify_sleep_tx_count(priv, sta_id, 1);
+ }
+
txq_id = skb_get_queue_mapping(skb);
if (ieee80211_is_data_qos(fc)) {
qc = ieee80211_get_qos_ctl(hdr);
@@ -930,6 +950,17 @@
ret = iwl_txq_update_write_ptr(priv, txq);
spin_unlock_irqrestore(&priv->lock, flags);
+ /*
+ * At this point the frame is "transmitted" successfully
+ * and we will get a TX status notification eventually,
+ * regardless of the value of ret. "ret" only indicates
+ * whether or not we should update the write pointer.
+ */
+
+ /* avoid atomic ops if it isn't an associated client */
+ if (sta_priv && sta_priv->client)
+ atomic_inc(&sta_priv->pending_frames);
+
if (ret)
return ret;
@@ -1074,6 +1105,24 @@
return ret ? ret : idx;
}
+static void iwl_tx_status(struct iwl_priv *priv, struct sk_buff *skb)
+{
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+ struct ieee80211_sta *sta;
+ struct iwl_station_priv *sta_priv;
+
+ sta = ieee80211_find_sta(priv->vif, hdr->addr1);
+ if (sta) {
+ sta_priv = (void *)sta->drv_priv;
+ /* avoid atomic ops if this isn't a client */
+ if (sta_priv->client &&
+ atomic_dec_return(&sta_priv->pending_frames) == 0)
+ ieee80211_sta_block_awake(priv->hw, sta, false);
+ }
+
+ ieee80211_tx_status_irqsafe(priv->hw, skb);
+}
+
int iwl_tx_queue_reclaim(struct iwl_priv *priv, int txq_id, int index)
{
struct iwl_tx_queue *txq = &priv->txq[txq_id];
@@ -1093,7 +1142,7 @@
q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd)) {
tx_info = &txq->txb[txq->q.read_ptr];
- ieee80211_tx_status_irqsafe(priv->hw, tx_info->skb[0]);
+ iwl_tx_status(priv, tx_info->skb[0]);
tx_info->skb[0] = NULL;
if (priv->cfg->ops->lib->txq_inval_byte_cnt_tbl)