From bf8b286f86fcc66d138fd992acfa37839340218d Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 30 Jun 2017 10:48:28 +0200 Subject: iwlwifi: mvm: defer setting IWL_MVM_STATUS_IN_HW_RESTART A hardware/firmware error may happen at any point in time. In particular, it might happen while mac80211 is in the middle of a flow. We observed the following situation: * mac80211 is in authentication flow, in ieee80211_prep_connection() * iwlwifi firmware crashes, but no error can be reported at this precise point (mostly because the driver method is void, but even if it wasn't we'd just shift to a race condition) * mac80211 continues the flow, trying to add the AP station * iwlwifi has already set its internal restart flag, and so thinks that adding the station is part of the restart and already set up, so it uses the information that's supposed to already be in the struct This can happen with any flow in mac80211 and with any information we try to preserve across hardware restarts. To fix this, only set a new HW_RESTART_REQUESTED flag and translate that to IN_HW_RESTART once mac80211 actually starts the restart by calling our start() method. As a consequence, any mac80211 flow in progress at the time of the restart will properly finish (certainly with errors), before the restart is attempted. This fixes https://bugzilla.kernel.org/show_bug.cgi?id=195299. Reported-by: djagoo Reported-by: Łukasz Siudut Signed-off-by: Johannes Berg Signed-off-by: Luca Coelho --- drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c') diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c index bcde1ba0f1c8..c7b1e58e3384 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c @@ -1084,7 +1084,13 @@ int __iwl_mvm_mac_start(struct iwl_mvm *mvm) lockdep_assert_held(&mvm->mutex); - if (test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status)) { + if (test_bit(IWL_MVM_STATUS_HW_RESTART_REQUESTED, &mvm->status)) { + /* + * Now convert the HW_RESTART_REQUESTED flag to IN_HW_RESTART + * so later code will - from now on - see that we're doing it. + */ + set_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status); + clear_bit(IWL_MVM_STATUS_HW_RESTART_REQUESTED, &mvm->status); /* Clean up some internal and mac80211 state on restart */ iwl_mvm_restart_cleanup(mvm); } else { -- cgit v1.2.3-55-g7522 From 7e39a00d593133ca8fcd3eef0409685e7c895ee6 Mon Sep 17 00:00:00 2001 From: Avraham Stern Date: Wed, 26 Jul 2017 15:08:45 +0300 Subject: iwlwifi: mvm: start mac queues when deferred tx frames are purged In AP mode, if a station is removed just as it is adding a new stream, the queue in question will remain stopped and no more TX will happen in this queue, leading to connection failures and other problems. This is because under DQA, when tx is deferred because a queue needs to be allocated, the mac queue for that TID is stopped until the new stream is added. If at this point the station that this stream belongs to is removed, all the deferred tx frames are purged, but the mac queue is not restarted. As a result, all following tx on this queue will not be transmitted. Fix this by starting the relevant mac queues when the deferred tx frames are purged. Fixes: 24afba7690e4 ("iwlwifi: mvm: support bss dynamic alloc/dealloc of queues") Signed-off-by: Avraham Stern Signed-off-by: Luca Coelho --- drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c') diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c index c7b1e58e3384..ce901be5fba8 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c @@ -2597,8 +2597,18 @@ static void iwl_mvm_purge_deferred_tx_frames(struct iwl_mvm *mvm, spin_lock_bh(&mvm_sta->lock); for (i = 0; i <= IWL_MAX_TID_COUNT; i++) { tid_data = &mvm_sta->tid_data[i]; - while ((skb = __skb_dequeue(&tid_data->deferred_tx_frames))) + + while ((skb = __skb_dequeue(&tid_data->deferred_tx_frames))) { + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + + /* + * The first deferred frame should've stopped the MAC + * queues, so we should never get a second deferred + * frame for the RA/TID. + */ + iwl_mvm_start_mac_queues(mvm, info->hw_queue); ieee80211_free_txskb(mvm->hw, skb); + } } spin_unlock_bh(&mvm_sta->lock); } -- cgit v1.2.3-55-g7522