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 X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 3C57DC43381 for ; Wed, 13 Mar 2019 20:43:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F0C262077B for ; Wed, 13 Mar 2019 20:43:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727101AbfCMUnc (ORCPT ); Wed, 13 Mar 2019 16:43:32 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:38208 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726263AbfCMUnc (ORCPT ); Wed, 13 Mar 2019 16:43:32 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id C228214D3C762; Wed, 13 Mar 2019 13:43:31 -0700 (PDT) Date: Wed, 13 Mar 2019 13:43:27 -0700 (PDT) Message-Id: <20190313.134327.1436563233974528424.davem@davemloft.net> To: Bryan.Whitehead@microchip.com Cc: netdev@vger.kernel.org, UNGLinuxDriver@microchip.com Subject: Re: [PATCH v1 net] lan743x: Fix TX Stall Issue From: David Miller In-Reply-To: <1552506948-6863-1-git-send-email-Bryan.Whitehead@microchip.com> References: <1552506948-6863-1-git-send-email-Bryan.Whitehead@microchip.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Wed, 13 Mar 2019 13:43:31 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Bryan Whitehead Date: Wed, 13 Mar 2019 15:55:48 -0400 > It has been observed that tx queue may stall while downloading > from certain web sites (example www.speedtest.net) > > The cause has been tracked down to a corner case where > the tx interrupt vector was disabled automatically, but > was not re enabled later. > > The lan743x has two mechanisms to enable/disable individual > interrupts. Interrupts can be enabled/disabled by individual > source, and they can also be enabled/disabled by individual > vector which has been mapped to the source. Both must be > enabled for interrupts to work properly. > > The TX code path, primarily uses the interrupt enable/disable of > the TX source bit, while leaving the vector enabled all the time. > > However, while investigating this issue it was noticed that > the driver requested the use of the vector auto clear feature. > > The test above revealed a case where the vector enable was > cleared unintentionally. > > This patch fixes the issue by deleting the lines that request > the vector auto clear feature to be used. > > Fixes: 23f0703c125b ("lan743x: Add main source files for new lan743x driver") > Signed-off-by: Bryan Whitehead Applied and queued up for -stable.