Return-path: Received: from mail-ww0-f44.google.com ([74.125.82.44]:42471 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932282Ab0JLMtu (ORCPT ); Tue, 12 Oct 2010 08:49:50 -0400 Received: by mail-ww0-f44.google.com with SMTP id 40so4973564wwj.1 for ; Tue, 12 Oct 2010 05:49:49 -0700 (PDT) From: Ido Yariv To: Luciano Coelho , linux-wireless@vger.kernel.org Cc: Ido Yariv Subject: [PATCH v3 4/4] wl1271: Fix TX queue low watermark handling Date: Tue, 12 Oct 2010 14:49:12 +0200 Message-Id: <1286887752-19321-5-git-send-email-ido@wizery.com> In-Reply-To: <1286887752-19321-1-git-send-email-ido@wizery.com> References: <1286887752-19321-1-git-send-email-ido@wizery.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: The number of entries in the TX queue is compared to the low watermark value each time TX completion interrupts are handled. However, the fact that a TX completion arrived does not necessarily mean there are any less skbs in the TX queue. In addition, a TX completion interrupt does not necessarily mean that there are any new available TX blocks. Thus, queuing TX work when the low watermark is reached might not be needed. Fix this by moving the low watermark handling to the TX work function, and avoid queuing TX work in this case. Signed-off-by: Ido Yariv --- drivers/net/wireless/wl12xx/wl1271_tx.c | 35 +++++++++++++++++++----------- 1 files changed, 22 insertions(+), 13 deletions(-) diff --git a/drivers/net/wireless/wl12xx/wl1271_tx.c b/drivers/net/wireless/wl12xx/wl1271_tx.c index a3a29ea..4b8218f 100644 --- a/drivers/net/wireless/wl12xx/wl1271_tx.c +++ b/drivers/net/wireless/wl12xx/wl1271_tx.c @@ -212,6 +212,20 @@ u32 wl1271_tx_enabled_rates_get(struct wl1271 *wl, u32 rate_set) return enabled_rates; } +static void handle_tx_low_watermark(struct wl1271 *wl) +{ + unsigned long flags; + + if (test_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags) && + skb_queue_len(&wl->tx_queue) <= WL1271_TX_QUEUE_LOW_WATERMARK) { + /* firmware buffer has space, restart queues */ + spin_lock_irqsave(&wl->wl_lock, flags); + ieee80211_wake_queues(wl->hw); + clear_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags); + spin_unlock_irqrestore(&wl->wl_lock, flags); + } +} + void wl1271_tx_work_locked(struct wl1271 *wl) { struct sk_buff *skb; @@ -225,6 +239,7 @@ void wl1271_tx_work_locked(struct wl1271 *wl) if (unlikely(test_and_clear_bit(WL1271_FLAG_STA_RATES_CHANGED, &wl->flags))) { unsigned long flags; + spin_lock_irqsave(&wl->wl_lock, flags); sta_rates = wl->sta_rate_set; spin_unlock_irqrestore(&wl->wl_lock, flags); @@ -285,6 +300,7 @@ out_ack: if (sent_packets) { /* interrupt the firmware with the new packets */ wl1271_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count); + handle_tx_low_watermark(wl); } out: @@ -399,19 +415,6 @@ void wl1271_tx_complete(struct wl1271 *wl) wl->tx_results_count++; } - - if (test_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags) && - skb_queue_len(&wl->tx_queue) <= WL1271_TX_QUEUE_LOW_WATERMARK) { - unsigned long flags; - - /* firmware buffer has space, restart queues */ - wl1271_debug(DEBUG_TX, "tx_complete: waking queues"); - spin_lock_irqsave(&wl->wl_lock, flags); - ieee80211_wake_queues(wl->hw); - clear_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags); - spin_unlock_irqrestore(&wl->wl_lock, flags); - ieee80211_queue_work(wl->hw, &wl->tx_work); - } } /* caller must hold wl->mutex */ @@ -426,6 +429,12 @@ void wl1271_tx_reset(struct wl1271 *wl) ieee80211_tx_status(wl->hw, skb); } + /* + * Make sure the driver is at a consistent state, in case this + * function is called from a context other than interface removal. + */ + handle_tx_low_watermark(wl); + for (i = 0; i < ACX_TX_DESCRIPTORS; i++) if (wl->tx_frames[i] != NULL) { skb = wl->tx_frames[i]; -- 1.7.0.4