From mboxrd@z Thu Jan 1 00:00:00 1970 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 5B0EAC19F2A for ; Thu, 11 Aug 2022 16:21:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237748AbiHKQV2 (ORCPT ); Thu, 11 Aug 2022 12:21:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237916AbiHKQU7 (ORCPT ); Thu, 11 Aug 2022 12:20:59 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA48EB02B3; Thu, 11 Aug 2022 09:03:16 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 8BC64B82182; Thu, 11 Aug 2022 16:03:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7CA56C433D6; Thu, 11 Aug 2022 16:03:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660233794; bh=dfGDc5y7t1OJDZv5DDOhjgv3vAFicA7oBOPSO6VEFVg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ue5BWd73wF3zzmgULqka0NNmbdwuECVo1I59zAbslPKkD36R/z9fvEK580HnCXfmE gMiWk7Y/A3JCy7svM4QFz7otUb9ydQ621cO04d7hMBaUH5GuTRdEYJnITQLZUG1ifO KkQ82rYvBqF7GUy8g6ZanNwQW18p306iODEDmIL8Xl/6CVAsdzxaAFxL5Qh0HfWeMW flHnKPyxGdL/0fjcFrxXdzvA0tWkso4WxnxYSdzm4rLY1MiEbRs3y1jd2tVy6t7+7l vvU5/kRMrQusCwkevgFmQMJb0RFGXZmyyv6e9eZ9N68u2jrBAmLBQcda4pY0MD7lgh PpkkJBW4BoY/w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: =?UTF-8?q?=C5=81ukasz=20Spintzyk?= , Greg Kroah-Hartman , Paolo Abeni , Sasha Levin , linux-usb@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 56/69] net/cdc_ncm: Increase NTB max RX/TX values to 64kb Date: Thu, 11 Aug 2022 11:56:05 -0400 Message-Id: <20220811155632.1536867-56-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220811155632.1536867-1-sashal@kernel.org> References: <20220811155632.1536867-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org From: Łukasz Spintzyk [ Upstream commit 5588d628027092e66195097bdf6835ddf64418b3 ] DisplayLink ethernet devices require NTB buffers larger then 32kb in order to run with highest performance. This patch is changing upper limit of the rx and tx buffers. Those buffers are initialized with CDC_NCM_NTB_DEF_SIZE_RX and CDC_NCM_NTB_DEF_SIZE_TX which is 16kb so by default no device is affected by increased limit. Rx and tx buffer is increased under two conditions: - Device need to advertise that it supports higher buffer size in dwNtbMaxInMaxSize and dwNtbMaxOutMaxSize. - cdc_ncm/rx_max and cdc_ncm/tx_max driver parameters must be adjusted with udev rule or ethtool. Summary of testing and performance results: Tests were performed on following devices: - DisplayLink DL-3xxx family device - DisplayLink DL-6xxx family device - ASUS USB-C2500 2.5G USB3 ethernet adapter - Plugable USB3 1G USB3 ethernet adapter - EDIMAX EU-4307 USB-C ethernet adapter - Dell DBQBCBC064 USB-C ethernet adapter Performance measurements were done with: - iperf3 between two linux boxes - http://openspeedtest.com/ instance running on local test machine Insights from tests results: - All except one from third party usb adapters were not affected by increased buffer size to their advertised dwNtbOutMaxSize and dwNtbInMaxSize. Devices were generally reaching 912-940Mbps both download and upload. Only EDIMAX adapter experienced decreased download size from 929Mbps to 827Mbps with iper3, with openspeedtest decrease was from 968Mbps to 886Mbps. - DisplayLink DL-3xxx family devices experienced performance increase with iperf3 download from 300Mbps to 870Mbps and upload from 782Mbps to 844Mbps. With openspeedtest download increased from 556Mbps to 873Mbps and upload from 727Mbps to 973Mbps - DiplayLink DL-6xxx family devices are not affected by increased buffer size. Signed-off-by: Łukasz Spintzyk Acked-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20220720060518.541-2-lukasz.spintzyk@synaptics.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- include/linux/usb/cdc_ncm.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h index f7cb3ddce7fb..2d207cb4837d 100644 --- a/include/linux/usb/cdc_ncm.h +++ b/include/linux/usb/cdc_ncm.h @@ -53,8 +53,8 @@ #define USB_CDC_NCM_NDP32_LENGTH_MIN 0x20 /* Maximum NTB length */ -#define CDC_NCM_NTB_MAX_SIZE_TX 32768 /* bytes */ -#define CDC_NCM_NTB_MAX_SIZE_RX 32768 /* bytes */ +#define CDC_NCM_NTB_MAX_SIZE_TX 65536 /* bytes */ +#define CDC_NCM_NTB_MAX_SIZE_RX 65536 /* bytes */ /* Initial NTB length */ #define CDC_NCM_NTB_DEF_SIZE_TX 16384 /* bytes */ -- 2.35.1