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Commit b9dccdb3 authored by Arik Nemtsov's avatar Arik Nemtsov Committed by Emmanuel Grumbach
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iwlwifi: mvm: ignore stale TDLS ch-switch responses 



During out-of-channel activities (e.g. scan) TDLS ch-switch responses from
a peer are kept in FW. These packets arrive only after the out-of-channel
activity is complete, which can be in the order of several seconds.

Since TDLS ch-sw has no dialog-token-like mechanism for distinguishing
sessions, use the GP2 time of the incoming ch-switch response to discern
validity. For this purpose record the GP2 time of an outgoing TDLS ch-sw
request and compare to the Rx time of the ch-sw response.
The methods works in practice since the GP2 time of FW-deferred Rx is
accurate and contains the real Rx timestamp.

Signed-off-by: default avatarArik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarEmmanuel Grumbach <emmanuel.grumbach@intel.com>
parent 5cb12701

drivers/net/wireless/iwlwifi/mvm/mvm.h

+3 −0
Original line number Diff line number Diff line
@@ -798,6 +798,9 @@ struct iwl_mvm { 
			struct cfg80211_chan_def chandef;

			struct sk_buff *skb; /* ch sw template */

			u32 ch_sw_tm_ie;



			/* timestamp of last ch-sw request sent (GP2 time) */

			u32 sent_timestamp;

		} peer;

	} tdls_cs;

drivers/net/wireless/iwlwifi/mvm/tdls.c

+13 −2
Original line number Diff line number Diff line
@@ -64,6 +64,8 @@ 
#include <linux/etherdevice.h>

#include "mvm.h"

#include "time-event.h"

#include "iwl-io.h"

#include "iwl-prph.h"



#define TU_TO_US(x) (x * 1024)

#define TU_TO_MS(x) (TU_TO_US(x) / 1000)
@@ -250,6 +252,11 @@ static void iwl_mvm_tdls_update_cs_state(struct iwl_mvm *mvm, 
		       iwl_mvm_tdls_cs_state_str(state));

	mvm->tdls_cs.state = state;



	/* we only send requests to our switching peer - update sent time */

	if (state == IWL_MVM_TDLS_SW_REQ_SENT)

		mvm->tdls_cs.peer.sent_timestamp =

			iwl_read_prph(mvm->trans, DEVICE_SYSTEM_TIME_REG);



	if (state == IWL_MVM_TDLS_SW_IDLE)

		mvm->tdls_cs.cur_sta_id = IWL_MVM_STATION_COUNT;

}
@@ -302,7 +309,7 @@ int iwl_mvm_rx_tdls_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb, 
static int

iwl_mvm_tdls_check_action(struct iwl_mvm *mvm,

			  enum iwl_tdls_channel_switch_type type,

			  const u8 *peer, bool peer_initiator)

			  const u8 *peer, bool peer_initiator, u32 timestamp)

{

	bool same_peer = false;

	int ret = 0;
@@ -341,6 +348,9 @@ iwl_mvm_tdls_check_action(struct iwl_mvm *mvm, 
		else if (type == TDLS_SEND_CHAN_SW_REQ)

			/* wait for idle before sending another request */

			ret = -EBUSY;

		else if (timestamp <= mvm->tdls_cs.peer.sent_timestamp)

			/* we got a stale response - ignore it */

			ret = -EINVAL;

		break;

	case IWL_MVM_TDLS_SW_RESP_RCVD:

		/*
@@ -399,7 +409,8 @@ iwl_mvm_tdls_config_channel_switch(struct iwl_mvm *mvm, 


	lockdep_assert_held(&mvm->mutex);



	ret = iwl_mvm_tdls_check_action(mvm, type, peer, peer_initiator);

	ret = iwl_mvm_tdls_check_action(mvm, type, peer, peer_initiator,

					timestamp);

	if (ret)

		return ret;