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=-6.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 6D05EC388F9 for ; Fri, 23 Oct 2020 22:39:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3465A20BED for ; Fri, 23 Oct 2020 22:39:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757764AbgJWWjx (ORCPT ); Fri, 23 Oct 2020 18:39:53 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:42490 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S461743AbgJWWjw (ORCPT ); Fri, 23 Oct 2020 18:39:52 -0400 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1kW5ig-003BXL-AQ; Sat, 24 Oct 2020 00:39:34 +0200 Date: Sat, 24 Oct 2020 00:39:34 +0200 From: Andrew Lunn To: Chris Packham Cc: vivien.didelot@gmail.com, f.fainelli@gmail.com, olteanv@gmail.com, davem@davemloft.net, kuba@kernel.org, linux@armlinux.org.uk, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/4] net: dsa: mv88e6xxx: Handle error in serdes_get_regs Message-ID: <20201023223934.GD745568@lunn.ch> References: <20201022012516.18720-1-chris.packham@alliedtelesis.co.nz> <20201022012516.18720-4-chris.packham@alliedtelesis.co.nz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201022012516.18720-4-chris.packham@alliedtelesis.co.nz> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 22, 2020 at 02:25:14PM +1300, Chris Packham wrote: > If the underlying read operation failed we would end up writing stale > data to the supplied buffer. This would end up with the last > successfully read value repeating. Fix this by only writing the data > when we know the read was good. This will mean that failed values will > return 0xffff. > > Signed-off-by: Chris Packham Reviewed-by: Andrew Lunn Andrew