From patchwork Mon Mar 29 07:58:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 412693 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DDAAC433E1 for ; Mon, 29 Mar 2021 08:17:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F1362619AB for ; Mon, 29 Mar 2021 08:17:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232480AbhC2IQn (ORCPT ); Mon, 29 Mar 2021 04:16:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:59040 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232944AbhC2IOv (ORCPT ); Mon, 29 Mar 2021 04:14:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 73E706044F; Mon, 29 Mar 2021 08:14:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617005691; bh=CrpmpYp6iEDvJ3ElKc0pQLCS9txrJmAob1jp4rhsW0Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dasrwGkPwn4jVFvANbjqKDUacWsZ1wqLpEUr8F6n7/K7sfLmTn3YVdfwzOjUxUDlh 1TaY4gj5wte0DXIsc4AJbZCuNnRMmjyPfWi3A2Diz6/xdJdj8Uq/vfm6UtAIe3dzal h1kBtcxRTPKWeiytIfbOjvYWASiEb4I5HKUKmspA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Robert Davies , Hayes Wang , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 083/111] r8152: limit the RX buffer size of RTL8153A for USB 2.0 Date: Mon, 29 Mar 2021 09:58:31 +0200 Message-Id: <20210329075617.978652956@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210329075615.186199980@linuxfoundation.org> References: <20210329075615.186199980@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Hayes Wang [ Upstream commit f91a50d8b51b5c8ef1cfb08115a005bba4250507 ] If the USB host controller is EHCI, the throughput is reduced from 300Mb/s to 60Mb/s, when the rx buffer size is modified from 16K to 32K. According to the EHCI spec, the maximum size of the qTD is 20K. Therefore, when the driver uses more than 20K buffer, the latency time of EHCI would be increased. And, it let the RTL8153A get worse throughput. However, the driver uses alloc_pages() for rx buffer, so I limit the rx buffer to 16K rather than 20K. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=205923 Fixes: ec5791c202ac ("r8152: separate the rx buffer size") Reported-by: Robert Davies Signed-off-by: Hayes Wang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/usb/r8152.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index 486cf511d2bf..f6d643ecaf39 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -5529,7 +5529,10 @@ static int rtl_ops_init(struct r8152 *tp) ops->in_nway = rtl8153_in_nway; ops->hw_phy_cfg = r8153_hw_phy_cfg; ops->autosuspend_en = rtl8153_runtime_enable; - tp->rx_buf_sz = 32 * 1024; + if (tp->udev->speed < USB_SPEED_SUPER) + tp->rx_buf_sz = 16 * 1024; + else + tp->rx_buf_sz = 32 * 1024; tp->eee_en = true; tp->eee_adv = MDIO_EEE_1000T | MDIO_EEE_100TX; break;