From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from rtits2.realtek.com.tw (rtits2.realtek.com [211.75.126.72]) (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 C5B3122157B; Wed, 7 Oct 2026 02:31:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=211.75.126.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791340313; cv=none; b=uF1nQUwqoTxo/t8e2DEitgnX9HKshsbmcGuBWynGrlSTbmEPXHiL95DK2IXW/9c+xe8xQVL55ngAt/9x10Vxgo4UtBuAG3cmUU783wUB7/C9RM4HV8G8iWBvQPXg9BpJAw56kqMG4a8ThM12DlOaY2Ohkj0wNzAs7ZrUGx/6gew= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791340313; c=relaxed/simple; bh=RWCrne7Kk1ulz7DBV5OOYrWoI2P0LZHXia1smq1H+H0=; h=From:To:CC:Subject:Date:Message-ID:References:In-Reply-To: Content-Type:MIME-Version; b=HSCofA7Np0YbvamAjyx2jVpThv/tWaEf9eTw/CvCQqvG4ED/HO3GCvRGpArDq00VqclEJWLPNoHU8QFEtC+X4+vlKvBf53teWTNC6VH4KPyOcNUpejAuXVYjXsXn6PBqkqLPXLrmtdZ9hOJGLB5bwqvjnHVLlj3kSPU8qBjWYgQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=realtek.com; spf=pass smtp.mailfrom=realtek.com; dkim=pass (2048-bit key) header.d=realtek.com header.i=@realtek.com header.b=rKnoYzGi; arc=none smtp.client-ip=211.75.126.72 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=realtek.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=realtek.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=realtek.com header.i=@realtek.com header.b="rKnoYzGi" X-SpamFilter-By: ArmorX SpamTrap 5.80 with qID 6972Vd5H23465184, This message is accepted by code: ctloc85258 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=realtek.com; s=dkim; t=1791340299; bh=U8IpDLuXGHqIJEqKxAV6k/3Dtp16wkOUMCLPBb2C/f8=; h=From:To:CC:Subject:Date:Message-ID:References:In-Reply-To: Content-Type:Content-Transfer-Encoding:MIME-Version; b=rKnoYzGiaF+7yvXLv6Bv5GTNXM2auTSBUEZMTM/CuIIMSq//HrEc0gnx1f9y2+YHe Klf+o1lPQpzV08vzFaV642EHgFsd/CCc55acLeIkKCVYGV9Dx/VWScGQ3Du5xx2MSa ZHMDLmPJkBxanucthhCHWISq6r9GTf5TBOSmGhqrQ11LIFfMZ2bgFUJ7eeys9E0Hah RmBE7CowhJNzsLkaOf2lYstObJYFjNtsvicQELeLBjeyHmWPsPgeoMUllLS1TpwL5z A3E+ZAIxu52RLtrlfiY3MuGuOxRBXCvSo7cdCf114bFkDwwucSi/akTJ2HHAAjDgm4 lCqkx3QFqmFYQ== Received: from mail.realtek.com (rtkexhmbs02.realtek.com.tw[172.21.6.41]) by rtits2.realtek.com.tw (8.15.2/3.29/5.94) with ESMTPS id 6972Vd5H23465184 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 7 Oct 2026 10:31:39 +0800 Received: from RTKEXHMBS01.realtek.com.tw (172.21.6.40) by RTKEXHMBS02.realtek.com.tw (172.21.6.41) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.49; Wed, 7 Oct 2026 10:31:39 +0800 Received: from RTKEXHMBS06.realtek.com.tw (10.21.1.56) by RTKEXHMBS01.realtek.com.tw (172.21.6.40) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.49; Wed, 7 Oct 2026 10:31:24 +0800 Received: from RTKEXHMBS06.realtek.com.tw ([::1]) by RTKEXHMBS06.realtek.com.tw ([fe80::b3cc:c263:b82d:e87c%10]) with mapi id 15.02.2562.049; Wed, 7 Oct 2026 10:31:24 +0800 From: Ping-Ke Shih To: Devin Wittmayer CC: "linux-wireless@vger.kernel.org" , Bitterblue Smith , Nick Morrow , "stable@vger.kernel.org" Subject: RE: [PATCH rtw-next] wifi: rtw89: usb: shorten the RX aggregation hold on RTL8922AU Thread-Topic: [PATCH rtw-next] wifi: rtw89: usb: shorten the RX aggregation hold on RTL8922AU Thread-Index: AQHdVcXLhUR7pyplckCU03EB/o2Zj7bxVR7Q Date: Wed, 7 Oct 2026 02:31:24 +0000 Message-ID: References: <20261006190618.258037-1-lucid_duck@justthetip.ca> In-Reply-To: <20261006190618.258037-1-lucid_duck@justthetip.ca> Accept-Language: en-US, zh-TW Content-Language: zh-TW Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Devin Wittmayer wrote: > The RTL8922AU holds received frames for up to a millisecond before > handing them to the host, a value carried over from the RTL8852CU. > That adds up to a millisecond of round trip, and under load at 160 MHz > the access point drops to lower rates and download suffers. >=20 > Shorten the hold on this chip. Upload is unchanged, and so is download > on a USB 2 port, where the bus is the limit.=20 Can I know the number of USB 2 port? Just curious, not blocking item. > The cost is some extra CPU at the same load. I think the major reason people want RX aggregation is that a chip is operating on a low-end CPU.=20 >=20 > RTL8922AU on USB 3 at 160 MHz, power save off for the round trip: >=20 > x86, 6 GHz x86, 5 GHz Pi 5, 6 GHz > before after before after before after > TCP down, 1 flow 613 1002 579 948 586 999 Mbps > TCP down, 8 flows 656 1187 629 1080 605 1108 Mbps > round trip 2.33 1.29 2.25 1.18 1.44 0.88 ms > busiest core, UDP 200M 8.4 12.8 8.3 12.9 2.3 2.8 % >=20 > Fixes: 32cee8a9bb66 ("wifi: rtw89: usb: Enable RX aggregation for RTL8922= AU") > Reported-by: Nick Morrow > Cc: stable@vger.kernel.org > Signed-off-by: Devin Wittmayer Acked-by: Ping-Ke Shih > --- > Ping-Ke, Bitterblue pointed me to you, since the 32 came from Realtek. > Realtek's 8852CU driver uses it as the default and also has a > small-packet mode that sets the hold to 1, the value this patch uses. > If the longer default is there for a reason these tests would miss, > please let me know, thank you. I can't find small-packet mode you mentioned, please share a link.=20 As I know the reason of longer default can benefit low-end CPU.=20 By the way, the TX aggregation is pending, because our experiments show no gain after the patch, so I don't send the patch. That means current platform is much better than what years ago. Ping-Ke