From 55df5afb13718cda49128fa5985556df91d07765 Mon Sep 17 00:00:00 2001 From: Arik Nemtsov Date: Sat, 3 Mar 2012 22:18:00 +0200 Subject: [PATCH] wl12xx: implement SW Tx watchdog Track freed FW blocks during Tx. If no blocks were freed during a predefined timeout, initiate a HW recovery. This helps in situations when the FW watchdog fails. Don't trigger recovery during activities that can temporarily stop Tx. This includes: - scanning - buffering packets for sleeping stations (AP role) - ROC on any role Signed-off-by: Arik Nemtsov Signed-off-by: Eliad Peller Signed-off-by: Luciano Coelho --- drivers/net/wireless/wl12xx/cmd.c | 8 +++ drivers/net/wireless/wl12xx/conf.h | 3 + drivers/net/wireless/wl12xx/main.c | 110 +++++++++++++++++++++++++++++++++++ drivers/net/wireless/wl12xx/scan.c | 6 ++ drivers/net/wireless/wl12xx/tx.c | 4 ++ drivers/net/wireless/wl12xx/tx.h | 1 + drivers/net/wireless/wl12xx/wl12xx.h | 3 + 7 files changed, 135 insertions(+) diff --git a/drivers/net/wireless/wl12xx/cmd.c b/drivers/net/wireless/wl12xx/cmd.c index 1ef212f..3414fc1 100644 --- a/drivers/net/wireless/wl12xx/cmd.c +++ b/drivers/net/wireless/wl12xx/cmd.c @@ -1818,6 +1818,14 @@ int wl12xx_croc(struct wl1271 *wl, u8 role_id) goto out; __clear_bit(role_id, wl->roc_map); + + /* + * Rearm the tx watchdog when removing the last ROC. This prevents + * recoveries due to just finished ROCs - when Tx hasn't yet had + * a chance to get out. + */ + if (find_first_bit(wl->roc_map, WL12XX_MAX_ROLES) >= WL12XX_MAX_ROLES) + wl12xx_rearm_tx_watchdog_locked(wl); out: return ret; } diff --git a/drivers/net/wireless/wl12xx/conf.h b/drivers/net/wireless/wl12xx/conf.h index cc50faa..3e581e1 100644 --- a/drivers/net/wireless/wl12xx/conf.h +++ b/drivers/net/wireless/wl12xx/conf.h @@ -690,6 +690,9 @@ struct conf_tx_settings { */ u8 tmpl_short_retry_limit; u8 tmpl_long_retry_limit; + + /* Time in ms for Tx watchdog timer to expire */ + u32 tx_watchdog_timeout; }; enum { diff --git a/drivers/net/wireless/wl12xx/main.c b/drivers/net/wireless/wl12xx/main.c index 95a76a5..3900236 100644 --- a/drivers/net/wireless/wl12xx/main.c +++ b/drivers/net/wireless/wl12xx/main.c @@ -217,6 +217,7 @@ static struct conf_drv_settings default_conf = { .basic_rate_5 = CONF_HW_BIT_RATE_6MBPS, .tmpl_short_retry_limit = 10, .tmpl_long_retry_limit = 10, + .tx_watchdog_timeout = 5000, }, .conn = { .wake_up_event = CONF_WAKE_UP_EVENT_DTIM, @@ -553,6 +554,80 @@ static void wl1271_rx_streaming_timer(unsigned long data) ieee80211_queue_work(wl->hw, &wlvif->rx_streaming_disable_work); } +/* wl->mutex must be taken */ +void wl12xx_rearm_tx_watchdog_locked(struct wl1271 *wl) +{ + /* if the watchdog is not armed, don't do anything */ + if (wl->tx_allocated_blocks == 0) + return; + + cancel_delayed_work(&wl->tx_watchdog_work); + ieee80211_queue_delayed_work(wl->hw, &wl->tx_watchdog_work, + msecs_to_jiffies(wl->conf.tx.tx_watchdog_timeout)); +} + +static void wl12xx_tx_watchdog_work(struct work_struct *work) +{ + struct delayed_work *dwork; + struct wl1271 *wl; + + dwork = container_of(work, struct delayed_work, work); + wl = container_of(dwork, struct wl1271, tx_watchdog_work); + + mutex_lock(&wl->mutex); + + if (unlikely(wl->state == WL1271_STATE_OFF)) + goto out; + + /* Tx went out in the meantime - everything is ok */ + if (unlikely(wl->tx_allocated_blocks == 0)) + goto out; + + /* + * if a ROC is in progress, we might not have any Tx for a long + * time (e.g. pending Tx on the non-ROC channels) + */ + if (find_first_bit(wl->roc_map, WL12XX_MAX_ROLES) < WL12XX_MAX_ROLES) { + wl1271_debug(DEBUG_TX, "No Tx (in FW) for %d ms due to ROC", + wl->conf.tx.tx_watchdog_timeout); + wl12xx_rearm_tx_watchdog_locked(wl); + goto out; + } + + /* + * if a scan is in progress, we might not have any Tx for a long + * time + */ + if (wl->scan.state != WL1271_SCAN_STATE_IDLE) { + wl1271_debug(DEBUG_TX, "No Tx (in FW) for %d ms due to scan", + wl->conf.tx.tx_watchdog_timeout); + wl12xx_rearm_tx_watchdog_locked(wl); + goto out; + } + + /* + * AP might cache a frame for a long time for a sleeping station, + * so rearm the timer if there's an AP interface with stations. If + * Tx is genuinely stuck we will most hopefully discover it when all + * stations are removed due to inactivity. + */ + if (wl->active_sta_count) { + wl1271_debug(DEBUG_TX, "No Tx (in FW) for %d ms. AP has " + " %d stations", + wl->conf.tx.tx_watchdog_timeout, + wl->active_sta_count); + wl12xx_rearm_tx_watchdog_locked(wl); + goto out; + } + + wl1271_error("Tx stuck (in FW) for %d ms. Starting recovery", + wl->conf.tx.tx_watchdog_timeout); + wl12xx_queue_recovery_work(wl); + +out: + mutex_unlock(&wl->mutex); +} + static void wl1271_conf_init(struct wl1271 *wl) { @@ -745,6 +820,18 @@ static void wl12xx_fw_status(struct wl1271 *wl, wl->tx_allocated_blocks -= freed_blocks; + /* + * If the FW freed some blocks: + * If we still have allocated blocks - re-arm the timer, Tx is + * not stuck. Otherwise, cancel the timer (no Tx currently). + */ + if (freed_blocks) { + if (wl->tx_allocated_blocks) + wl12xx_rearm_tx_watchdog_locked(wl); + else + cancel_delayed_work(&wl->tx_watchdog_work); + } + avail = le32_to_cpu(status->tx_total) - wl->tx_allocated_blocks; /* @@ -1418,6 +1505,7 @@ int wl1271_plt_stop(struct wl1271 *wl) cancel_work_sync(&wl->netstack_work); cancel_work_sync(&wl->recovery_work); cancel_delayed_work_sync(&wl->elp_work); + cancel_delayed_work_sync(&wl->tx_watchdog_work); mutex_lock(&wl->mutex); wl1271_power_off(wl); @@ -1789,6 +1877,7 @@ static void wl1271_op_stop(struct ieee80211_hw *hw) cancel_work_sync(&wl->netstack_work); cancel_work_sync(&wl->tx_work); cancel_delayed_work_sync(&wl->elp_work); + cancel_delayed_work_sync(&wl->tx_watchdog_work); /* let's notify MAC80211 about the remaining pending TX frames */ wl12xx_tx_reset(wl, true); @@ -2218,6 +2307,12 @@ static void __wl1271_op_remove_interface(struct wl1271 *wl, if (wl->scan.state != WL1271_SCAN_STATE_IDLE && wl->scan_vif == vif) { + /* + * Rearm the tx watchdog just before idling scan. This + * prevents just-finished scans from triggering the watchdog + */ + wl12xx_rearm_tx_watchdog_locked(wl); + wl->scan.state = WL1271_SCAN_STATE_IDLE; memset(wl->scan.scanned_ch, 0, sizeof(wl->scan.scanned_ch)); wl->scan_vif = NULL; @@ -3129,6 +3224,13 @@ static void wl1271_op_cancel_hw_scan(struct ieee80211_hw *hw, if (ret < 0) goto out_sleep; } + + /* + * Rearm the tx watchdog just before idling scan. This + * prevents just-finished scans from triggering the watchdog + */ + wl12xx_rearm_tx_watchdog_locked(wl); + wl->scan.state = WL1271_SCAN_STATE_IDLE; memset(wl->scan.scanned_ch, 0, sizeof(wl->scan.scanned_ch)); wl->scan_vif = NULL; @@ -4138,6 +4240,13 @@ void wl1271_free_sta(struct wl1271 *wl, struct wl12xx_vif *wlvif, u8 hlid) __clear_bit(hlid, (unsigned long *)&wl->ap_fw_ps_map); wl12xx_free_link(wl, wlvif, &hlid); wl->active_sta_count--; + + /* + * rearm the tx watchdog when the last STA is freed - give the FW a + * chance to return STA-buffered packets before complaining. + */ + if (wl->active_sta_count == 0) + wl12xx_rearm_tx_watchdog_locked(wl); } static int wl12xx_sta_add(struct wl1271 *wl, @@ -5212,6 +5321,7 @@ static struct ieee80211_hw *wl1271_alloc_hw(void) INIT_WORK(&wl->tx_work, wl1271_tx_work); INIT_WORK(&wl->recovery_work, wl1271_recovery_work); INIT_DELAYED_WORK(&wl->scan_complete_work, wl1271_scan_complete_work); + INIT_DELAYED_WORK(&wl->tx_watchdog_work, wl12xx_tx_watchdog_work); wl->freezable_wq = create_freezable_workqueue("wl12xx_wq"); if (!wl->freezable_wq) { diff --git a/drivers/net/wireless/wl12xx/scan.c b/drivers/net/wireless/wl12xx/scan.c index e43a6b2..fcba055 100644 --- a/drivers/net/wireless/wl12xx/scan.c +++ b/drivers/net/wireless/wl12xx/scan.c @@ -55,6 +55,12 @@ void wl1271_scan_complete_work(struct work_struct *work) vif = wl->scan_vif; wlvif = wl12xx_vif_to_data(vif); + /* + * Rearm the tx watchdog just before idling scan. This + * prevents just-finished scans from triggering the watchdog + */ + wl12xx_rearm_tx_watchdog_locked(wl); + wl->scan.state = WL1271_SCAN_STATE_IDLE; memset(wl->scan.scanned_ch, 0, sizeof(wl->scan.scanned_ch)); wl->scan.req = NULL; diff --git a/drivers/net/wireless/wl12xx/tx.c b/drivers/net/wireless/wl12xx/tx.c index 8f78fdd..43ae491 100644 --- a/drivers/net/wireless/wl12xx/tx.c +++ b/drivers/net/wireless/wl12xx/tx.c @@ -226,6 +226,10 @@ static int wl1271_tx_allocate(struct wl1271 *wl, struct wl12xx_vif *wlvif, wl->tx_blocks_available -= total_blocks; wl->tx_allocated_blocks += total_blocks; + /* If the FW was empty before, arm the Tx watchdog */ + if (wl->tx_allocated_blocks == total_blocks) + wl12xx_rearm_tx_watchdog_locked(wl); + ac = wl1271_tx_get_queue(skb_get_queue_mapping(skb)); wl->tx_allocated_pkts[ac]++; diff --git a/drivers/net/wireless/wl12xx/tx.h b/drivers/net/wireless/wl12xx/tx.h index e3977b5..5cf8c32 100644 --- a/drivers/net/wireless/wl12xx/tx.h +++ b/drivers/net/wireless/wl12xx/tx.h @@ -227,5 +227,6 @@ void wl12xx_rearm_rx_streaming(struct wl1271 *wl, unsigned long *active_hlids); /* from main.c */ void wl1271_free_sta(struct wl1271 *wl, struct wl12xx_vif *wlvif, u8 hlid); +void wl12xx_rearm_tx_watchdog_locked(struct wl1271 *wl); #endif diff --git a/drivers/net/wireless/wl12xx/wl12xx.h b/drivers/net/wireless/wl12xx/wl12xx.h index 6e13a30..749a15a 100644 --- a/drivers/net/wireless/wl12xx/wl12xx.h +++ b/drivers/net/wireless/wl12xx/wl12xx.h @@ -495,6 +495,9 @@ struct wl1271 { /* last wlvif we transmitted from */ struct wl12xx_vif *last_wlvif; + + /* work to fire when Tx is stuck */ + struct delayed_work tx_watchdog_work; }; struct wl1271_station { -- 2.7.4