iwlwifi: mvm: Use CS tx block bit for AP/GO

An AP/GO may perform the channel switch slightly before its stations.
This scenario may result in packet loss, since the transmission may start
before the client is actually on a new channel. In order to prevent
potential packet loss disable tx to all the stations when the channel
switch flow starts. Clear the disable_tx bit when a station is seen on a
target channel, or after IWL_MVM_CS_UNBLOCK_TX_TIMEOUT beacons on a new
channel. In addition call ieee80211_sta_block_awake in order to inform
mac80211 that the frames for this station should be buffered.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h
index db496c5c73fc..7b308c4834f6 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/iwlwifi/mvm/mvm.h
@@ -95,6 +95,12 @@
  */
 #define IWL_MVM_CHANNEL_SWITCH_MARGIN 4
 
+/*
+ * Number of beacons to transmit on a new channel until we unblock tx to
+ * the stations, even if we didn't identify them on a new channel
+ */
+#define IWL_MVM_CS_UNBLOCK_TX_TIMEOUT 3
+
 enum iwl_mvm_tx_fifo {
 	IWL_MVM_TX_FIFO_BK = 0,
 	IWL_MVM_TX_FIFO_BE,
@@ -671,6 +677,8 @@ struct iwl_mvm {
 	bool ps_disabled;
 
 	struct ieee80211_vif __rcu *csa_vif;
+	struct ieee80211_vif __rcu *csa_tx_blocked_vif;
+	u8 csa_tx_block_bcn_timeout;
 
 	/* system time of last beacon (for AP/GO interface) */
 	u32 ap_last_beacon_gp2;