From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f51.google.com (mail-wr1-f51.google.com [209.85.221.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 59C2D3B47CA for ; Mon, 7 Sep 2026 19:09:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788808148; cv=none; b=OvTWaYsZB680MBYiHOt4OlUmzftyNJKmINsYO2jGeCx+j6Ri0tdbpjdMJGEOSf+4KBt5aIn+B3Tp2IkVFEF6hyCG11HJzjkhP1Ul/dG/4lvzOcv2S4OhJRFglMdAaMiMquNVpYcnLvHfvE80BaQThbVC/iMQ7lkjLxidgwsVOdU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788808148; c=relaxed/simple; bh=ztWP+24QaHA6Xw67hhL9tmJxZPi3tbSdQjf6uZ9EM6I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Uehfu4ezPkNW+crgMTfz427RyeeM29mWbDTwcwkU5K4+KGfhy88RP64bEqi3JnEeV3C5onBbcsOYQ0k8tmXb4sjw96cRiOkgJWv2RZbKh/CmDnC1/V/oChpfB72wYcR4LXDQnIUiTne7fRYRRFHNjrjEaON7+Vo894sTEUiX3Os= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Btwu77J7; arc=none smtp.client-ip=209.85.221.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Btwu77J7" Received: by mail-wr1-f51.google.com with SMTP id ffacd0b85a97d-482f9309813so3441345f8f.1 for ; Mon, 07 Sep 2026 12:09:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1788808144; x=1789412944; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=aWWUTNxueDekJa6qk76yBRcI4kBuGeARV4/mQXdjmJg=; b=Btwu77J7bhZktSG10DgtFxKA/3g75DMy+S6vuOEDfknsLovw/BrwZqZflwD+957zso P4VOk+II/qPV23AcU6LQlmruvX7Ts/nVDeKyZ+JCx2unASCybivqXit1qJhiHHM1UCe5 eF1aAEW6S3DS1VSF/0Sj+tP/LCkRKTd/jykDO0D2b+JaTPLWHY08ZYCXIxefI/pldSH8 VxaVCzDFenZMPcF2hOO9GmIWLXTbNQmzuCR4Udm1NgAHHheoQyYz135e1Y+t2wX+WQPc 4otDeLngINXV/dU9EnQKLTE4gA+2N5E1kf4CcHRpeK6bKckFuiDP8QgMS680MO8O8dSC 1FqQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788808144; x=1789412944; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=aWWUTNxueDekJa6qk76yBRcI4kBuGeARV4/mQXdjmJg=; b=iaSQSFFF7odA4vWZG7ZGZfWBZG3tsJYaoQKg/8agpUPoRm2OT2B6bIUl0LoCnqnvV1 SPFNu+4AbVm+Y6GpurSmGnXrnw2jnKfPKxtZM63EYgMm9VtVcn3sBooJQ8kdBufXEZcA 2khYGUeIc1jpQP+SGrpj02U+8mniaY0ktxmGkdcTPWlrmkGSQGXLoJPE2g0qu9gv7vUe lqHM1D6HoyNgmwWlmnuPJFTiwNtDY3XNVdWbFSPCkSdHFOb0TKjezT40rTgs7vltbwVt MjHFSeqo5D+v3PmxI5t2OAw0uPAfygtPt7uotalYI+EUPvleF+/8X2SDPm4t67kt7Vww bSZg== X-Forwarded-Encrypted: i=1; AKwUvBwV/BMZMJAYwrGyBt0Sd7a9PNd6bDjZZjQ8wm7NH5TzVu1e+S00AnhRv9VcSFtQb0dl05vmAkTS1OrzhHsO+A==@vger.kernel.org X-Gm-Message-State: AFuF++nxcyJm4b43O1UanhJE+QtYHjsEJssFZ73Dx710GIuCgZ7/vGLB LjaTyQc5lnAeektYQaRs1FyS7uM9zh4XeAgmryy3jr8rH4bRknSmt+RZ X-Gm-Gg: AYBFou1TxVZGdFmnZWqxXzKLCBNruXvSUOu+FDIjA4sqR5coxb/QeWiHJE+3NGsG67/ rBd281oqhZVHXrZvjsrinHnND5tFxUw4Rd2K+2krojkGZO/QdBpyNX4qrfWy+SArrkJBGvRTWtr mfKwsUfvI+P7fdlTFejtka+MxfqTv57nQp8b2ZwlIGQHXf4bbcbrixH92Y4VPyNnrJ7fy7XpHOt uclEezt8p9KHoaFAtmbT6ajG6g0ZgGGyM+sOBkh/Abk5gCplvu+xB3K18v23qOhP/43uTr9gUN9 l5xTLC9uiuQPHzI8O44PvyPG58HILKdRyNSkK4pxn/zQ/9+CjO+HNkX2GsXmYAU+4jQhO4XijSB +iEwdpXUnTvumMK49/1L2DJzXKYcVET+9bhlOBv+w+7efL6gbIULN8L/LSsTWHsZYW3/u84LcPQ +CtJN7WFIrSymMdCP7NRzHyEN4rA32fRYYY0zelrUY/ebexJdUWmBX/W4vhQ+Vm86KuJ9qeeuxo pL7 X-Received: by 2002:a05:6000:2001:b0:47f:96e3:530e with SMTP id ffacd0b85a97d-48587285526mr24874171f8f.8.1788808144235; Mon, 07 Sep 2026 12:09:04 -0700 (PDT) Received: from deb05.proceq.com ([213.160.61.66]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-485885bf3f0sm33365544f8f.33.2026.09.07.12.09.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Sep 2026 12:09:03 -0700 (PDT) From: Mehmet Fide To: Ping-Ke Shih Cc: Bitterblue Smith , linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, mehmet.fide@screeningeagle.com Subject: [PATCH rtw-next v2 1/3] wifi: rtw88: usb: bound what the driver feeds the after-DTIM queue Date: Mon, 7 Sep 2026 21:08:59 +0200 Message-ID: <20260907190901.1056945-2-mehmet.fide@gmail.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260907190901.1056945-1-mehmet.fide@gmail.com> References: <20260907190901.1056945-1-mehmet.fide@gmail.com> Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Mehmet Fide Frames routed to the high queue are transmitted right after DTIM beacons only, inside the ATIM window, while they wait in the shared TX page pool. The driver puts no limit on how many it hands over, so as long as one station dozes, any sustained broadcast or multicast traffic outruns the drain and empties the pool: measured on an RTL8822BU AP with a single client in power save and ~40 frames/s of mDNS chatter, the free page count at 0x240 goes from 1803 to 16 in about 100 seconds and stays there for as long as the traffic lasts. From that point every other transmit queues behind the backlog, authentication responses arrive too late for anyone to join, and the reserved page download fails ("error beacon valid"). The AP keeps beaconing and only a reboot recovers. Feed the high queue through a small budget that refills below the measured drain rate (about 3 frames per DTIM, ~15/s at dtim_period 2 on the default 2 TU ATIM window); whatever exceeds the budget leaves on its access category queue right away. The high queue backlog is now bounded by the burst size under any load, so the page pool cannot run dry, at the price that a dozing station may miss part of a broadcast storm. Signed-off-by: Mehmet Fide --- v2: - macro RTW_USB_HIQ_REFILL_INTERVAL for HZ / 10, RTW_USB_HIQ_BUDGET_MAX (Ping-Ke) - 'budget' instead of 'token': hiq_budget, rtw_usb_hiq_take_budget() (Ping-Ke) - refill bookkeeping rewritten as elapsed / interval and hiq_refill = jiffies - elapsed % interval, with a comment (Ping-Ke) - blank lines after spin_lock_irqsave() and before spin_unlock_irqrestore() (Ping-Ke) drivers/net/wireless/realtek/rtw88/usb.c | 41 ++++++++++++++++++++++-- drivers/net/wireless/realtek/rtw88/usb.h | 5 +++ 2 files changed, 43 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/realtek/rtw88/usb.c b/drivers/net/wireless/realtek/rtw88/usb.c index c90802919473..5482e44f4a88 100644 --- a/drivers/net/wireless/realtek/rtw88/usb.c +++ b/drivers/net/wireless/realtek/rtw88/usb.c @@ -562,7 +562,37 @@ static int rtw_usb_write_data_h2c(struct rtw_dev *rtwdev, u8 *buf, u32 size) return rtw_usb_write_data(rtwdev, &pkt_info, buf); } -static u8 rtw_usb_tx_queue_mapping_to_qsel(struct sk_buff *skb) +#define RTW_USB_HIQ_REFILL_INTERVAL (HZ / 10) /* jiffies per unit of budget */ +#define RTW_USB_HIQ_BUDGET_MAX 16 + +static bool rtw_usb_hiq_take_budget(struct rtw_usb *rtwusb) +{ + unsigned long flags, elapsed, add; + bool ok; + + spin_lock_irqsave(&rtwusb->hiq_lock, flags); + + elapsed = jiffies - rtwusb->hiq_refill; + add = elapsed / RTW_USB_HIQ_REFILL_INTERVAL; + if (add) { + rtwusb->hiq_budget = min_t(unsigned long, rtwusb->hiq_budget + add, + RTW_USB_HIQ_BUDGET_MAX); + /* The part of the current interval that has not completed yet + * keeps counting toward the next unit + */ + rtwusb->hiq_refill = jiffies - elapsed % RTW_USB_HIQ_REFILL_INTERVAL; + } + ok = rtwusb->hiq_budget > 0; + if (ok) + rtwusb->hiq_budget--; + + spin_unlock_irqrestore(&rtwusb->hiq_lock, flags); + + return ok; +} + +static u8 rtw_usb_tx_queue_mapping_to_qsel(struct rtw_usb *rtwusb, + struct sk_buff *skb) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); @@ -573,7 +603,8 @@ static u8 rtw_usb_tx_queue_mapping_to_qsel(struct sk_buff *skb) qsel = TX_DESC_QSEL_MGMT; else if (is_broadcast_ether_addr(hdr->addr1) || is_multicast_ether_addr(hdr->addr1)) - qsel = (info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM) ? + qsel = (info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM) && + rtw_usb_hiq_take_budget(rtwusb) ? TX_DESC_QSEL_HIGH : skb->priority; else if (skb_get_queue_mapping(skb) <= IEEE80211_AC_BK) qsel = skb->priority; @@ -593,7 +624,7 @@ static int rtw_usb_tx_write(struct rtw_dev *rtwdev, u8 *pkt_desc; int ep; - pkt_info->qsel = rtw_usb_tx_queue_mapping_to_qsel(skb); + pkt_info->qsel = rtw_usb_tx_queue_mapping_to_qsel(rtwusb, skb); pkt_desc = skb_push(skb, chip->tx_pkt_desc_sz); memset(pkt_desc, 0, chip->tx_pkt_desc_sz); ep = qsel_to_ep(rtwusb, pkt_info->qsel); @@ -1034,6 +1065,10 @@ static int rtw_usb_init_tx(struct rtw_dev *rtwdev) struct rtw_usb *rtwusb = rtw_get_usb_priv(rtwdev); int i; + spin_lock_init(&rtwusb->hiq_lock); + rtwusb->hiq_budget = RTW_USB_HIQ_BUDGET_MAX; + rtwusb->hiq_refill = jiffies; + rtwusb->txwq = create_singlethread_workqueue("rtw88_usb: tx wq"); if (!rtwusb->txwq) { rtw_err(rtwdev, "failed to create TX work queue\n"); diff --git a/drivers/net/wireless/realtek/rtw88/usb.h b/drivers/net/wireless/realtek/rtw88/usb.h index 9b695b688b24..94ff21dd0846 100644 --- a/drivers/net/wireless/realtek/rtw88/usb.h +++ b/drivers/net/wireless/realtek/rtw88/usb.h @@ -75,6 +75,11 @@ struct rtw_usb { u8 out_ep[RTW_USB_EP_MAX]; int qsel_to_ep[TX_DESC_QSEL_MAX]; + /* protects hiq_budget and hiq_refill */ + spinlock_t hiq_lock; + u32 hiq_budget; + unsigned long hiq_refill; + struct workqueue_struct *txwq, *rxwq; struct sk_buff_head tx_queue[RTW_USB_EP_MAX]; -- 2.55.0