From a600852a9d00be08c539307a42729fd46b0a654e Mon Sep 17 00:00:00 2001 From: Emmanuel Grumbach Date: Thu, 27 Jul 2017 15:34:12 +0300 Subject: [PATCH] iwlwifi: mvm: don't WARN when a legit race happens in A-MPDU When we start an Rx A-MPDU session, we first get the AddBA request, then we send an ADD_STA command to the firmware that will reply with a BAID which is a hardware resource that tracks the BA session. This BAID will appear on each and every frame that we get from the firwmare until the A-MPDU session is torn down. In the Rx path, we look at this BAID to manage the reordering buffer. This flow is inherently racy since the hardware will start to put the BAID in the frames it receives even if the firmware hasn't sent the response to the ADD_STA command. This basically means that the driver can get frames with a valid BAID that it doesn't know yet. When that happens, the driver used to WARN. Fix this by simply not WARN in this case. When the driver will know abou the BAID, it will initialise the relevant states and the next frame with a valid BAID will refresh them. Fixes: b915c10174fb ("iwlwifi: mvm: add reorder buffer per queue") Signed-off-by: Emmanuel Grumbach Signed-off-by: Luca Coelho --- drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c index f3e608196369..71c8b800ffa9 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c @@ -636,9 +636,9 @@ static bool iwl_mvm_reorder(struct iwl_mvm *mvm, baid_data = rcu_dereference(mvm->baid_map[baid]); if (!baid_data) { - WARN(!(reorder & IWL_RX_MPDU_REORDER_BA_OLD_SN), - "Received baid %d, but no data exists for this BAID\n", - baid); + IWL_DEBUG_RX(mvm, + "Got valid BAID but no baid allocated, bypass the re-ordering buffer. Baid %d reorder 0x%x\n", + baid, reorder); return false; } @@ -759,7 +759,9 @@ static void iwl_mvm_agg_rx_received(struct iwl_mvm *mvm, data = rcu_dereference(mvm->baid_map[baid]); if (!data) { - WARN_ON(!(reorder_data & IWL_RX_MPDU_REORDER_BA_OLD_SN)); + IWL_DEBUG_RX(mvm, + "Got valid BAID but no baid allocated, bypass the re-ordering buffer. Baid %d reorder 0x%x\n", + baid, reorder_data); goto out; } -- 2.20.1