Return-path: Received: from wolverine02.qualcomm.com ([199.106.114.251]:44197 "EHLO wolverine02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753494Ab2EYJz7 (ORCPT ); Fri, 25 May 2012 05:55:59 -0400 From: Vasanthakumar Thiagarajan To: CC: , Subject: [PATCH 2/2] ath6kl: Fix unstable downlink throughput Date: Fri, 25 May 2012 15:25:53 +0530 Message-ID: <1337939753-14491-2-git-send-email-vthiagar@qca.qualcomm.com> (sfid-20120525_115601_993533_D801D1F6) In-Reply-To: <1337939753-14491-1-git-send-email-vthiagar@qca.qualcomm.com> References: <1337939753-14491-1-git-send-email-vthiagar@qca.qualcomm.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: There is frequent downlink throughput drop to 0 when operating at the signal level between -42dBm to -53dBm. This has been root caused to the delay in releasing pending a-mpdu subframes in reorder buffer. Right now the timeout value is 400ms, there is also a race condition where timeout handler can be delayed to run at an extra timeout interval. This patch reduces the timout interval to reasonable 100ms and makes sure releasing pending frames are not skipped in the timeout handler by removing the flag (rxtid->progress) which can delay the timeout logic. Reported-by: Yu Yanzhi Signed-off-by: Vasanthakumar Thiagarajan --- drivers/net/wireless/ath/ath6kl/core.h | 3 +- drivers/net/wireless/ath/ath6kl/txrx.c | 44 ++++++++++++++----------------- 2 files changed, 21 insertions(+), 26 deletions(-) diff --git a/drivers/net/wireless/ath/ath6kl/core.h b/drivers/net/wireless/ath/ath6kl/core.h index b1bc6bc..a827bd7 100644 --- a/drivers/net/wireless/ath/ath6kl/core.h +++ b/drivers/net/wireless/ath/ath6kl/core.h @@ -215,7 +215,7 @@ enum ath6kl_hw_flags { #define AGGR_NUM_OF_FREE_NETBUFS 16 -#define AGGR_RX_TIMEOUT 400 /* in ms */ +#define AGGR_RX_TIMEOUT 100 /* in ms */ #define WMI_TIMEOUT (2 * HZ) @@ -264,7 +264,6 @@ struct skb_hold_q { struct rxtid { bool aggr; - bool progress; bool timer_mon; u16 win_sz; u16 seq_next; diff --git a/drivers/net/wireless/ath/ath6kl/txrx.c b/drivers/net/wireless/ath/ath6kl/txrx.c index 60723be..6fe730d 100644 --- a/drivers/net/wireless/ath/ath6kl/txrx.c +++ b/drivers/net/wireless/ath/ath6kl/txrx.c @@ -1186,28 +1186,27 @@ static bool aggr_process_recv_frm(struct aggr_info_conn *agg_conn, u8 tid, aggr_deque_frms(agg_conn, tid, 0, 1); if (agg_conn->timer_scheduled) - rxtid->progress = true; - else - for (idx = 0 ; idx < rxtid->hold_q_sz; idx++) { - spin_lock_bh(&rxtid->lock); - if (rxtid->hold_q[idx].skb) { - /* - * There is a frame in the queue and no - * timer so start a timer to ensure that - * the frame doesn't remain stuck - * forever. - */ - agg_conn->timer_scheduled = true; - mod_timer(&agg_conn->timer, - (jiffies + - HZ * (AGGR_RX_TIMEOUT) / 1000)); - rxtid->progress = false; - rxtid->timer_mon = true; - spin_unlock_bh(&rxtid->lock); - break; - } + return is_queued; + + for (idx = 0 ; idx < rxtid->hold_q_sz; idx++) { + spin_lock_bh(&rxtid->lock); + if (rxtid->hold_q[idx].skb) { + /* + * There is a frame in the queue and no + * timer so start a timer to ensure that + * the frame doesn't remain stuck + * forever. + */ + agg_conn->timer_scheduled = true; + mod_timer(&agg_conn->timer, + (jiffies + + HZ * (AGGR_RX_TIMEOUT) / 1000)); + rxtid->timer_mon = true; spin_unlock_bh(&rxtid->lock); + break; } + spin_unlock_bh(&rxtid->lock); + } return is_queued; } @@ -1612,7 +1611,7 @@ static void aggr_timeout(unsigned long arg) rxtid = &aggr_conn->rx_tid[i]; stats = &aggr_conn->stat[i]; - if (!rxtid->aggr || !rxtid->timer_mon || rxtid->progress) + if (!rxtid->aggr || !rxtid->timer_mon) continue; stats->num_timeouts++; @@ -1635,7 +1634,6 @@ static void aggr_timeout(unsigned long arg) if (rxtid->hold_q[j].skb) { aggr_conn->timer_scheduled = true; rxtid->timer_mon = true; - rxtid->progress = false; spin_unlock_bh(&rxtid->lock); break; } @@ -1667,7 +1665,6 @@ static void aggr_delete_tid_state(struct aggr_info_conn *aggr_conn, u8 tid) aggr_deque_frms(aggr_conn, tid, 0, 0); rxtid->aggr = false; - rxtid->progress = false; rxtid->timer_mon = false; rxtid->win_sz = 0; rxtid->seq_next = 0; @@ -1746,7 +1743,6 @@ void aggr_conn_init(struct ath6kl_vif *vif, struct aggr_info *aggr_info, for (i = 0; i < NUM_OF_TIDS; i++) { rxtid = &aggr_conn->rx_tid[i]; rxtid->aggr = false; - rxtid->progress = false; rxtid->timer_mon = false; skb_queue_head_init(&rxtid->q); spin_lock_init(&rxtid->lock); -- 1.7.0.4