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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 8E295C10F03 for ; Tue, 23 Apr 2019 17:26:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6705820835 for ; Tue, 23 Apr 2019 17:26:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729441AbfDWR0N (ORCPT ); Tue, 23 Apr 2019 13:26:13 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:39730 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729222AbfDWR0M (ORCPT ); Tue, 23 Apr 2019 13:26:12 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (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 E9878133E8184; Tue, 23 Apr 2019 10:26:11 -0700 (PDT) Date: Tue, 23 Apr 2019 10:26:08 -0700 (PDT) Message-Id: <20190423.102608.343500084156113302.davem@davemloft.net> To: mw@semihalf.com Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org, antoine.tenart@bootlin.com, jaz@semihalf.com, gregory.clement@bootlin.com, nadavh@marvell.com, thomas.petazzoni@bootlin.com, linux@armlinux.org.uk, tn@semihalf.com, stefanc@marvell.com Subject: Re: [net: PATCH] net: mvpp2: disable link IRQ waiting for IDLE frames From: David Miller In-Reply-To: References: <20190228093627.vtfglsl2djenohlm@shell.armlinux.org.uk> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=euc-kr Content-Transfer-Encoding: 8bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 23 Apr 2019 10:26:12 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marcin Wojtas Date: Tue, 23 Apr 2019 18:08:00 +0200 > Hi David, Rusell, > > czw., 28 lut 2019 o 14:58 Marcin Wojtas napisaİİ(a): >> >> Hi Russell, >> >> czw., 28 lut 2019 o 10:36 Russell King - ARM Linux admin >> napisaİİ(a): >> > >> > On Wed, Feb 27, 2019 at 06:47:32PM +0100, Marcin Wojtas wrote: >> > > Current version of the driver was configuring XLG MAC >> > > in a way to wait 3 IDLE frames before allowing for the >> > > link-up interrupt to be triggered. This resulted in an >> > > issue, preventing to detect the link change during RX >> > > traffic on the interface. Fix that. >> > >> > What about noise sensitivity? Does this now mean that on boards such as >> > Macchiatobin Single Shot or Clearfog GT9k where the serdes is connected >> > directly to a SFP cage, that noise on the serdes lines triggers a link >> > indication? >> > >> >> Afaik waiting for idle frames is not required by any standard. In fact >> this feature of the XLG MAC caused a risk that after dropping the link >> during data transfer it would never go up again until remote peer >> stops it. >> >> I tested it on 3 different boards with SerDes directly connected to >> the SFP cage and I'm also not aware of any reporte about >> noise-triggered false link interrupts in XLG MAC (proprietary Marvell >> mvpp2x driver did not use waiting 3 idle frames feature). I'd rather >> assume the MAC is not vulnerable to it, and only properly established >> link can trigger an event. >> > > This patch seems to get forgotten - any objections to merge it? If there is agreement, please repost it. Thank you.