From 7f0a7c671cdc0396f99b60b77bd02e2dee7c4838 Mon Sep 17 00:00:00 2001 From: Andrei Otcheretianski Date: Sun, 4 May 2014 11:48:12 +0300 Subject: [PATCH] iwlwifi: mvm: Reflect GO channel switch in NoA According to the spec, GO/AP should perform the channel switch just before "beacon 0". However, since the exact timing isn't defined, it may result in a sudden GO disappearance from the channel. Prevent potential packet loss when performing the CS by scheduling NoA time event and executing the channel switch flow when a notification from fw is received. Signed-off-by: Andrei Otcheretianski Reviewed-by: Johannes Berg Signed-off-by: Emmanuel Grumbach --- drivers/net/wireless/iwlwifi/mvm/fw-api.h | 3 + drivers/net/wireless/iwlwifi/mvm/mac-ctxt.c | 41 ++++++++--- drivers/net/wireless/iwlwifi/mvm/mac80211.c | 5 +- drivers/net/wireless/iwlwifi/mvm/mvm.h | 12 +++ drivers/net/wireless/iwlwifi/mvm/time-event.c | 73 +++++++++++++++++++ drivers/net/wireless/iwlwifi/mvm/time-event.h | 29 ++++++++ 6 files changed, 153 insertions(+), 10 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/mvm/fw-api.h b/drivers/net/wireless/iwlwifi/mvm/fw-api.h index 6c479de3b8d4..99329edcd99f 100644 --- a/drivers/net/wireless/iwlwifi/mvm/fw-api.h +++ b/drivers/net/wireless/iwlwifi/mvm/fw-api.h @@ -538,6 +538,9 @@ enum iwl_time_event_type { /* WiDi Sync Events */ TE_WIDI_TX_SYNC, + /* Channel Switch NoA */ + TE_P2P_GO_CSA_NOA, + TE_MAX }; /* MAC_EVENT_TYPE_API_E_VER_1 */ diff --git a/drivers/net/wireless/iwlwifi/mvm/mac-ctxt.c b/drivers/net/wireless/iwlwifi/mvm/mac-ctxt.c index 19bd696bd6f8..a176d008dab1 100644 --- a/drivers/net/wireless/iwlwifi/mvm/mac-ctxt.c +++ b/drivers/net/wireless/iwlwifi/mvm/mac-ctxt.c @@ -67,6 +67,7 @@ #include "iwl-prph.h" #include "fw-api.h" #include "mvm.h" +#include "time-event.h" const u8 iwl_mvm_ac_to_tx_fifo[] = { IWL_MVM_TX_FIFO_VO, @@ -1200,6 +1201,35 @@ int iwl_mvm_mac_ctxt_remove(struct iwl_mvm *mvm, struct ieee80211_vif *vif) return 0; } +static void iwl_mvm_csa_count_down(struct iwl_mvm *mvm, + struct ieee80211_vif *csa_vif, u32 gp2) +{ + struct iwl_mvm_vif *mvmvif = + iwl_mvm_vif_from_mac80211(csa_vif); + + if (!ieee80211_csa_is_complete(csa_vif)) { + int c = ieee80211_csa_update_counter(csa_vif); + + iwl_mvm_mac_ctxt_beacon_changed(mvm, csa_vif); + if (csa_vif->p2p && + !iwl_mvm_te_scheduled(&mvmvif->time_event_data) && gp2) { + u32 rel_time = (c + 1) * + csa_vif->bss_conf.beacon_int - + IWL_MVM_CHANNEL_SWITCH_TIME; + u32 apply_time = gp2 + rel_time * 1024; + + iwl_mvm_schedule_csa_noa(mvm, csa_vif, + IWL_MVM_CHANNEL_SWITCH_TIME - + IWL_MVM_CHANNEL_SWITCH_MARGIN, + apply_time); + } + } else if (!iwl_mvm_te_scheduled(&mvmvif->time_event_data)) { + /* we don't have CSA NoA scheduled yet, switch now */ + ieee80211_csa_finish(csa_vif); + RCU_INIT_POINTER(mvm->csa_vif, NULL); + } +} + int iwl_mvm_rx_beacon_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb, struct iwl_device_cmd *cmd) @@ -1234,15 +1264,8 @@ int iwl_mvm_rx_beacon_notif(struct iwl_mvm *mvm, csa_vif = rcu_dereference_protected(mvm->csa_vif, lockdep_is_held(&mvm->mutex)); - if (unlikely(csa_vif && csa_vif->csa_active)) { - if (!ieee80211_csa_is_complete(csa_vif)) { - ieee80211_csa_update_counter(csa_vif); - iwl_mvm_mac_ctxt_beacon_changed(mvm, csa_vif); - } else { - ieee80211_csa_finish(csa_vif); - RCU_INIT_POINTER(mvm->csa_vif, NULL); - } - } + if (unlikely(csa_vif && csa_vif->csa_active)) + iwl_mvm_csa_count_down(mvm, csa_vif, mvm->ap_last_beacon_gp2); return 0; } diff --git a/drivers/net/wireless/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/iwlwifi/mvm/mac80211.c index 984a1e75aad0..4a0350fc4b4e 100644 --- a/drivers/net/wireless/iwlwifi/mvm/mac80211.c +++ b/drivers/net/wireless/iwlwifi/mvm/mac80211.c @@ -1608,8 +1608,11 @@ static void iwl_mvm_stop_ap_ibss(struct ieee80211_hw *hw, mutex_lock(&mvm->mutex); /* Handle AP stop while in CSA */ - if (rcu_access_pointer(mvm->csa_vif) == vif) + if (rcu_access_pointer(mvm->csa_vif) == vif) { + iwl_mvm_remove_time_event(mvm, mvmvif, + &mvmvif->time_event_data); RCU_INIT_POINTER(mvm->csa_vif, NULL); + } mvmvif->ap_ibss_active = false; mvm->ap_last_beacon_gp2 = 0; diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h index 5bb42af8886b..db496c5c73fc 100644 --- a/drivers/net/wireless/iwlwifi/mvm/mvm.h +++ b/drivers/net/wireless/iwlwifi/mvm/mvm.h @@ -83,6 +83,18 @@ #define IWL_RSSI_OFFSET 50 #define IWL_MVM_MISSED_BEACONS_THRESHOLD 8 +/* + * The CSA NoA is scheduled IWL_MVM_CHANNEL_SWITCH_TIME TUs before "beacon 0" + * TBTT. This value should be big enough to ensure that we switch in time. + */ +#define IWL_MVM_CHANNEL_SWITCH_TIME 40 + +/* + * This value (in TUs) is used to fine tune the CSA NoA end time which should + * be just before "beacon 0" TBTT. + */ +#define IWL_MVM_CHANNEL_SWITCH_MARGIN 4 + enum iwl_mvm_tx_fifo { IWL_MVM_TX_FIFO_BK = 0, IWL_MVM_TX_FIFO_BE, diff --git a/drivers/net/wireless/iwlwifi/mvm/time-event.c b/drivers/net/wireless/iwlwifi/mvm/time-event.c index 80100f6cc12a..ae52613b97f2 100644 --- a/drivers/net/wireless/iwlwifi/mvm/time-event.c +++ b/drivers/net/wireless/iwlwifi/mvm/time-event.c @@ -138,6 +138,41 @@ static void iwl_mvm_roc_finished(struct iwl_mvm *mvm) schedule_work(&mvm->roc_done_wk); } +static void iwl_mvm_csa_noa_start(struct iwl_mvm *mvm) +{ + struct ieee80211_vif *csa_vif; + + rcu_read_lock(); + + csa_vif = rcu_dereference(mvm->csa_vif); + if (!csa_vif || !csa_vif->csa_active) + goto out_unlock; + + IWL_DEBUG_TE(mvm, "CSA NOA started\n"); + + /* + * CSA NoA is started but we still have beacons to + * transmit on the current channel. + * So we just do nothing here and the switch + * will be performed on the last TBTT. + */ + if (!ieee80211_csa_is_complete(csa_vif)) { + IWL_WARN(mvm, "CSA NOA started too early\n"); + goto out_unlock; + } + + ieee80211_csa_finish(csa_vif); + + rcu_read_unlock(); + + RCU_INIT_POINTER(mvm->csa_vif, NULL); + + return; + +out_unlock: + rcu_read_unlock(); +} + static bool iwl_mvm_te_check_disconnect(struct iwl_mvm *mvm, struct ieee80211_vif *vif, const char *errmsg) @@ -213,6 +248,14 @@ static void iwl_mvm_te_handle_notif(struct iwl_mvm *mvm, set_bit(IWL_MVM_STATUS_ROC_RUNNING, &mvm->status); iwl_mvm_ref(mvm, IWL_MVM_REF_ROC); ieee80211_ready_on_channel(mvm->hw); + } else if (te_data->vif->type == NL80211_IFTYPE_AP) { + if (le32_to_cpu(notif->status)) + iwl_mvm_csa_noa_start(mvm); + else + IWL_DEBUG_TE(mvm, "CSA NOA failed to start\n"); + + /* we don't need it anymore */ + iwl_mvm_te_clear_data(mvm, te_data); } } else { IWL_WARN(mvm, "Got TE with unknown action\n"); @@ -538,3 +581,33 @@ void iwl_mvm_stop_p2p_roc(struct iwl_mvm *mvm) iwl_mvm_roc_finished(mvm); } + +int iwl_mvm_schedule_csa_noa(struct iwl_mvm *mvm, + struct ieee80211_vif *vif, + u32 duration, u32 apply_time) +{ + struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif); + struct iwl_mvm_time_event_data *te_data = &mvmvif->time_event_data; + struct iwl_time_event_cmd time_cmd = {}; + + lockdep_assert_held(&mvm->mutex); + + if (te_data->running) { + IWL_DEBUG_TE(mvm, "CS NOA is already scheduled\n"); + return -EBUSY; + } + + time_cmd.action = cpu_to_le32(FW_CTXT_ACTION_ADD); + time_cmd.id_and_color = + cpu_to_le32(FW_CMD_ID_AND_COLOR(mvmvif->id, mvmvif->color)); + time_cmd.id = cpu_to_le32(TE_P2P_GO_CSA_NOA); + time_cmd.apply_time = cpu_to_le32(apply_time); + time_cmd.max_frags = TE_V2_FRAG_NONE; + time_cmd.duration = cpu_to_le32(duration); + time_cmd.repeat = 1; + time_cmd.interval = cpu_to_le32(1); + time_cmd.policy = cpu_to_le16(TE_V2_NOTIF_HOST_EVENT_START | + TE_V2_ABSENCE); + + return iwl_mvm_time_event_send_add(mvm, vif, te_data, &time_cmd); +} diff --git a/drivers/net/wireless/iwlwifi/mvm/time-event.h b/drivers/net/wireless/iwlwifi/mvm/time-event.h index 4a61c8c02372..2f48a90d4ad3 100644 --- a/drivers/net/wireless/iwlwifi/mvm/time-event.h +++ b/drivers/net/wireless/iwlwifi/mvm/time-event.h @@ -214,4 +214,33 @@ void iwl_mvm_te_clear_data(struct iwl_mvm *mvm, void iwl_mvm_roc_done_wk(struct work_struct *wk); +/** + * iwl_mvm_schedule_csa_noa - request NoA for channel switch + * @mvm: the mvm component + * @vif: the virtual interface for which the channel switch is issued + * @duration: the duration of the NoA in TU. + * @apply_time: NoA start time in GP2. + * + * This function is used to schedule NoA time event and is used to perform + * the channel switch flow. + */ +int iwl_mvm_schedule_csa_noa(struct iwl_mvm *mvm, + struct ieee80211_vif *vif, + u32 duration, u32 apply_time); + +/** + * iwl_mvm_te_scheduled - check if the fw received the TE cmd + * @te_data: the time event data that corresponds to that time event + * + * This function returns true iff this TE is added to the fw. + */ +static inline bool +iwl_mvm_te_scheduled(struct iwl_mvm_time_event_data *te_data) +{ + if (!te_data) + return false; + + return !!te_data->uid; +} + #endif /* __time_event_h__ */ -- 2.20.1