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

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h
index fc80b7b43b21..ed097268a1bc 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;