From b9dccdb33c4dc86922d025d02e91715ad9510732 Mon Sep 17 00:00:00 2001 From: Arik Nemtsov Date: Thu, 22 Jan 2015 14:24:44 +0200 Subject: [PATCH] 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: Arik Nemtsov Reviewed-by: Johannes Berg Signed-off-by: Emmanuel Grumbach --- drivers/net/wireless/iwlwifi/mvm/mvm.h | 3 +++ drivers/net/wireless/iwlwifi/mvm/tdls.c | 15 +++++++++++++-- 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h index fc80b7b..ed09726 100644 --- a/drivers/net/wireless/iwlwifi/mvm/mvm.h +++ b/drivers/net/wireless/iwlwifi/mvm/mvm.h @@ -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; diff --git a/drivers/net/wireless/iwlwifi/mvm/tdls.c b/drivers/net/wireless/iwlwifi/mvm/tdls.c index ea1831c..a87b506 100644 --- a/drivers/net/wireless/iwlwifi/mvm/tdls.c +++ b/drivers/net/wireless/iwlwifi/mvm/tdls.c @@ -64,6 +64,8 @@ #include #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 @@ out: 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; -- 2.7.4