From patchwork Thu Dec 23 01:14:06 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: 527994 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 0CC70C43217 for ; Thu, 23 Dec 2021 01:14:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345854AbhLWBOI (ORCPT ); Wed, 22 Dec 2021 20:14:08 -0500 Received: from o1.ptr2625.egauge.net ([167.89.112.53]:17760 "EHLO o1.ptr2625.egauge.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238369AbhLWBOH (ORCPT ); Wed, 22 Dec 2021 20:14:07 -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=emRedEXnN1E6Sca8nTmnylU6pLvfF71PWPx92q9deco=; b=Op0A18i9PVkUdlsJon3r7sJVA+uM9i5UwiX/lsv8rSrubQTNq6lINUOnGDqkl85vgR0D L5B4FLVb69DTzotAVTuPSBaSXA2ToMkCotY2KXRuYVdf50hDCCWwmHcZVOlxE9/70VY6BF oLCsPNU6rc8m3DNeiOjuFMpZPorEkIgStW+5gyUa2YNsflQ9+iEQNTmtyX5u2dHjUwWyc2 lrRXafceBZ4x2Gfd0PifmBFMFxCHfdHAaFU6b7xOcTX0NmzcgMbma82/NmavOpxJP1QH/r E1XEbkgK39i7oQkOoUn35A7V4AiAqXq2A8A/Kw4hWTDsOlO/4l+OmvjS2jJK1VCQ== Received: by filterdrecv-64fcb979b9-7lnp4 with SMTP id filterdrecv-64fcb979b9-7lnp4-1-61C3CD5D-36 2021-12-23 01:14:05.795334457 +0000 UTC m=+8644592.725894849 Received: from pearl.egauge.net (unknown) by geopod-ismtpd-6-0 (SG) with ESMTP id P5TgjB1ZSFKLRRrKRnDvVg Thu, 23 Dec 2021 01:14:05.577 +0000 (UTC) Received: by pearl.egauge.net (Postfix, from userid 1000) id D47DE700604; Wed, 22 Dec 2021 18:14:04 -0700 (MST) From: David Mosberger-Tang Subject: [PATCH v2 02/50] wilc1000: switch txq_event from completion to waitqueue Date: Thu, 23 Dec 2021 01:14:06 +0000 (UTC) Message-Id: <20211223011358.4031459-3-davidm@egauge.net> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211223011358.4031459-1-davidm@egauge.net> References: <20211223011358.4031459-1-davidm@egauge.net> MIME-Version: 1.0 X-SG-EID: +kMxBqj35EdRUKoy8diX1j4AXmPtd302oan+iXZuF8m2Nw4HRW2irNspffT/khET6RJF6+Prbl0h/EtF1rRLvKKbokcqBZrOnU5kEpG8h+syelvS85jzqTtTcv7YHcinBYmG949gzYNeS+CPI21kQiP7YmP1MedO60V8pEhFGOBd10okyUtsBu7T9PvInMPjvAeIPsHSjoC7t1Sp7cStInnp01xhPqxamxTfGzHEr0j+7a70R+PU3Hkn3CetHkL6jToN6bok6N2HazAG7QD0zg== 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 643bddaae32ad..d5969f2e369c4 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 f4fc2cc392bd0..c07f58a86bc76 100644 --- a/drivers/net/wireless/microchip/wilc1000/netdev.h +++ b/drivers/net/wireless/microchip/wilc1000/netdev.h @@ -237,7 +237,7 @@ 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 c4da14147dd04..26fa7078acffd 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)