iwlwifi: dvm: handle FLUSH ampdu actions from mac80211

Until now we didn't handle properly the FLUSH ampdu action
coming from mac80211. This could result in SCD queue leak:
mac80211 would STOP_FLUSH an AMPDU Tx session and remove
the station. If we had still packets on the ring, we
wouldn't deallocate the SCD queue and wait for it to be
empty.
The indication of the queue being empty comes from the Tx
response flow which relies on the tid_data structure. The
problem is that this structure has been cleared when the
station has been removed.
In order to solve this issue, block in the STOP_FLUSH
ampdu_action until the SCD queue is flushed, and only then,
let mac80211 move forward to remove the station.
iwlagn_txfifo_flush had to be enhanced to allow this.

The bug fixed here caused the "txq_id mismatch: 12 0" print.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/net/wireless/iwlwifi/dvm/agn.h b/drivers/net/wireless/iwlwifi/dvm/agn.h
index 76b762e48703..e575b9b0cda8 100644
--- a/drivers/net/wireless/iwlwifi/dvm/agn.h
+++ b/drivers/net/wireless/iwlwifi/dvm/agn.h
@@ -178,7 +178,7 @@ int iwlagn_hw_valid_rtc_data_addr(u32 addr);
 /* lib */
 int iwlagn_send_tx_power(struct iwl_priv *priv);
 void iwlagn_temperature(struct iwl_priv *priv);
-int iwlagn_txfifo_flush(struct iwl_priv *priv);
+int iwlagn_txfifo_flush(struct iwl_priv *priv, u32 scd_q_msk);
 void iwlagn_dev_txfifo_flush(struct iwl_priv *priv);
 int iwlagn_send_beacon_cmd(struct iwl_priv *priv);
 int iwl_send_statistics_request(struct iwl_priv *priv,
@@ -212,6 +212,8 @@ int iwlagn_tx_agg_oper(struct iwl_priv *priv, struct ieee80211_vif *vif,
                         struct ieee80211_sta *sta, u16 tid, u8 buf_size);
 int iwlagn_tx_agg_stop(struct iwl_priv *priv, struct ieee80211_vif *vif,
                        struct ieee80211_sta *sta, u16 tid);
+int iwlagn_tx_agg_flush(struct iwl_priv *priv, struct ieee80211_vif *vif,
+                        struct ieee80211_sta *sta, u16 tid);
 int iwlagn_rx_reply_compressed_ba(struct iwl_priv *priv,
                                    struct iwl_rx_cmd_buffer *rxb,
                                    struct iwl_device_cmd *cmd);