From patchwork Sat Dec 18 23:54:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Mosberger-Tang X-Patchwork-Id: 525827 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC5C1C4321E for ; Sat, 18 Dec 2021 23:54:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235029AbhLRXyY (ORCPT ); Sat, 18 Dec 2021 18:54:24 -0500 Received: from o1.ptr2625.egauge.net ([167.89.112.53]:25214 "EHLO o1.ptr2625.egauge.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234587AbhLRXyS (ORCPT ); Sat, 18 Dec 2021 18:54:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=egauge.net; h=from:subject:in-reply-to:references:mime-version:to:cc: content-transfer-encoding:content-type; s=sgd; bh=lEJOszgCw0TFSxZvSVioKcU+0PoQE8Pc6r25UeeIg7A=; b=S/B1mMakfozT+C0PYycwp9fQiE8/uAqHELHPIMeGMZV+snaVjZ0NTDJn3pPnWMziw3/5 m88sAqBYj6v9D2ZARJ+P7RJLv927q8ESqxGi+OIEWB02+RtC/Q/S+Fxn2kWsxzGMPsHYRB 00JYKb1A2bdrUKTnWOA28QN4AWMwYxDpUsntvqKycFliOOb/adXCwXH2NT+aHfx3NtN1S9 3zZoM7dYZMjI/+RXJNqZVLU+YQmUJo7ID7cH3OZ3Z6jdVPQyat87OHrfsKflWbZC+IZVKK E9qDzoHYRJ1JYunc2W3zwsuQaoLxBcje+Z04v8lgZ/RWxQyTrRvuy9LHg3bkLiVQ== Received: by filterdrecv-7bf5c69d5-fb76v with SMTP id filterdrecv-7bf5c69d5-fb76v-1-61BE74A8-A 2021-12-18 23:54:16.307699886 +0000 UTC m=+1581798.970762200 Received: from pearl.egauge.net (unknown) by geopod-ismtpd-1-1 (SG) with ESMTP id BtctVw9tSLegk_x0es2y0w Sat, 18 Dec 2021 23:54:16.141 +0000 (UTC) Received: by pearl.egauge.net (Postfix, from userid 1000) id 8704D7005B6; Sat, 18 Dec 2021 16:54:15 -0700 (MST) From: David Mosberger-Tang Subject: [PATCH 02/23] wilc1000: switch txq_event from completion to waitqueue Date: Sat, 18 Dec 2021 23:54:16 +0000 (UTC) Message-Id: <20211218235404.3963475-3-davidm@egauge.net> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211218235404.3963475-1-davidm@egauge.net> References: <20211218235404.3963475-1-davidm@egauge.net> MIME-Version: 1.0 X-SG-EID: +kMxBqj35EdRUKoy8diX1j4AXmPtd302oan+iXZuF8m2Nw4HRW2irNspffT/khET6RJF6+Prbl0h/EtF1rRLvF2Lvk30d1zpJ0jP8DPK7uiSg+PB55J4rl/Xo2H8/0KuHpLlqO9wlby2SgTh3Y8nZTUBZLKX+W8sCnEKQLRwfT/rC0sly3dGPiq+OqFwQEeSh8GcBdCjth4cU2uVKSeYA/7oYTDKGmH0uW2DqJ1BhsMpAbrx+nJo6LDELKu49Z4Q/3nndoWt18u+0pv6c2GhzA== To: Ajay Singh Cc: Claudiu Beznea , Kalle Valo , "David S. Miller" , Jakub Kicinski , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, David Mosberger-Tang X-Entity-ID: Xg4JGAcGrJFIz2kDG9eoaQ== Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Completion structs are essentially counting semaphores: every complete() call wakes up exactly one thread, either immediately (when there are waiters queued) or in the future (when a waiter arrives). This isn't really the appropriate synchronization structure for the wilc1000 transmit queue handler (wilc_wlan_handle_txq) because it will consume zero, one, or more packets on each call. Instead, use a waitqueue as a condition variable: wake_up_interruptible() wakes up the tx queue handler from a call to wait_event_interruptible() whenever something interesting happens and it then takes the appropriate action. This has a couple of benefits: - Since the transmit queue handler often transfers multiple packets to the chip on each call, repeated calls to wait_for_completion() when there is no actual work to do are avoided. - When the transmit queue handler cannot transfer any packets at all, it'll simply give up the current time slice and then tries again. Previously, the transmit would stall until a new packet showed up (which potentially could cause extended stalls). It would be even better to wait for a "tx queue not full" interrupt but, sadly, I'm told the wilc1000 firmware doesn't provide that. - There is no longer any need for wilc_wlan_txq_filter_dup_tcp_ack() to adjust the completion structs wait count by calling wait_for_completion_timeout() for each dropped packet. Signed-off-by: David Mosberger-Tang --- drivers/net/wireless/microchip/wilc1000/cfg80211.c | 2 +- drivers/net/wireless/microchip/wilc1000/netdev.c | 13 +++++++++---- drivers/net/wireless/microchip/wilc1000/netdev.h | 2 +- drivers/net/wireless/microchip/wilc1000/wlan.c | 12 ++---------- 4 files changed, 13 insertions(+), 16 deletions(-) diff --git a/drivers/net/wireless/microchip/wilc1000/cfg80211.c b/drivers/net/wireless/microchip/wilc1000/cfg80211.c index 8d8378bafd9b0..be387a8abb6af 100644 --- a/drivers/net/wireless/microchip/wilc1000/cfg80211.c +++ b/drivers/net/wireless/microchip/wilc1000/cfg80211.c @@ -1692,7 +1692,7 @@ static void wlan_init_locks(struct wilc *wl) spin_lock_init(&wl->txq_spinlock); mutex_init(&wl->txq_add_to_head_cs); - init_completion(&wl->txq_event); + init_waitqueue_head(&wl->txq_event); init_completion(&wl->cfg_event); init_completion(&wl->sync_event); init_completion(&wl->txq_thread_started); diff --git a/drivers/net/wireless/microchip/wilc1000/netdev.c b/drivers/net/wireless/microchip/wilc1000/netdev.c index 03e3485d7e7fa..4dd7c8137c204 100644 --- a/drivers/net/wireless/microchip/wilc1000/netdev.c +++ b/drivers/net/wireless/microchip/wilc1000/netdev.c @@ -144,10 +144,12 @@ static int wilc_txq_task(void *vp) int ret; u32 txq_count; struct wilc *wl = vp; + long timeout; complete(&wl->txq_thread_started); while (1) { - wait_for_completion(&wl->txq_event); + wait_event_interruptible(wl->txq_event, + (wl->txq_entries > 0 || wl->close)); if (wl->close) { complete(&wl->txq_thread_started); @@ -170,6 +172,11 @@ static int wilc_txq_task(void *vp) } srcu_read_unlock(&wl->srcu, srcu_idx); } + if (ret == WILC_VMM_ENTRY_FULL_RETRY) { + timeout = msecs_to_jiffies(1); + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(timeout); + } } while (ret == WILC_VMM_ENTRY_FULL_RETRY && !wl->close); } return 0; @@ -419,12 +426,11 @@ static void wlan_deinitialize_threads(struct net_device *dev) wl->close = 1; - complete(&wl->txq_event); - if (wl->txq_thread) { kthread_stop(wl->txq_thread); wl->txq_thread = NULL; } + wake_up_interruptible(&wl->txq_event); } static void wilc_wlan_deinitialize(struct net_device *dev) @@ -446,7 +452,6 @@ static void wilc_wlan_deinitialize(struct net_device *dev) wl->hif_func->disable_interrupt(wl); mutex_unlock(&wl->hif_cs); } - complete(&wl->txq_event); wlan_deinitialize_threads(dev); deinit_irq(dev); diff --git a/drivers/net/wireless/microchip/wilc1000/netdev.h b/drivers/net/wireless/microchip/wilc1000/netdev.h index fd0cb01e538a2..65cf296a8689e 100644 --- a/drivers/net/wireless/microchip/wilc1000/netdev.h +++ b/drivers/net/wireless/microchip/wilc1000/netdev.h @@ -235,7 +235,7 @@ struct wilc { struct completion cfg_event; struct completion sync_event; - struct completion txq_event; + wait_queue_head_t txq_event; struct completion txq_thread_started; struct task_struct *txq_thread; diff --git a/drivers/net/wireless/microchip/wilc1000/wlan.c b/drivers/net/wireless/microchip/wilc1000/wlan.c index 721e6131125e8..fafeabe2537a3 100644 --- a/drivers/net/wireless/microchip/wilc1000/wlan.c +++ b/drivers/net/wireless/microchip/wilc1000/wlan.c @@ -75,7 +75,7 @@ static void wilc_wlan_txq_add_to_tail(struct net_device *dev, u8 q_num, spin_unlock_irqrestore(&wilc->txq_spinlock, flags); - complete(&wilc->txq_event); + wake_up_interruptible(&wilc->txq_event); } static void wilc_wlan_txq_add_to_head(struct wilc_vif *vif, u8 q_num, @@ -94,7 +94,7 @@ static void wilc_wlan_txq_add_to_head(struct wilc_vif *vif, u8 q_num, spin_unlock_irqrestore(&wilc->txq_spinlock, flags); mutex_unlock(&wilc->txq_add_to_head_cs); - complete(&wilc->txq_event); + wake_up_interruptible(&wilc->txq_event); } #define NOT_TCP_ACK (-1) @@ -196,7 +196,6 @@ static void wilc_wlan_txq_filter_dup_tcp_ack(struct net_device *dev) struct wilc *wilc = vif->wilc; struct tcp_ack_filter *f = &vif->ack_filter; u32 i = 0; - u32 dropped = 0; unsigned long flags; spin_lock_irqsave(&wilc->txq_spinlock, flags); @@ -226,7 +225,6 @@ static void wilc_wlan_txq_filter_dup_tcp_ack(struct net_device *dev) tqe->tx_complete_func(tqe->priv, tqe->status); kfree(tqe); - dropped++; } } } @@ -239,12 +237,6 @@ static void wilc_wlan_txq_filter_dup_tcp_ack(struct net_device *dev) f->pending_base = 0; spin_unlock_irqrestore(&wilc->txq_spinlock, flags); - - while (dropped > 0) { - wait_for_completion_timeout(&wilc->txq_event, - msecs_to_jiffies(1)); - dropped--; - } } void wilc_enable_tcp_ack_filter(struct wilc_vif *vif, bool value)