Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755264AbaFBPC1 (ORCPT ); Mon, 2 Jun 2014 11:02:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:11602 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751848AbaFBPCZ (ORCPT ); Mon, 2 Jun 2014 11:02:25 -0400 Date: Mon, 2 Jun 2014 17:01:50 +0200 From: Veaceslav Falico To: Jiri Pirko Cc: Michal Privoznik , davem@davemloft.net, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH] net-sysfs: Report link speed as signed integer Message-ID: <20140602150150.GF6295@redhat.com> References: <06d53256e3bf2d0deedb16249082200500da3ee6.1401718809.git.mprivozn@redhat.com> <20140602143557.GA2925@minipsycho.orion> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20140602143557.GA2925@minipsycho.orion> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 02, 2014 at 04:35:57PM +0200, Jiri Pirko wrote: >Mon, Jun 02, 2014 at 04:25:15PM CEST, mprivozn@redhat.com wrote: >>The link speed is available at /sys/class/net/$nic/speed. >>However, the speed is printed in unsigned integer format. This >>makes userspace applications read an incorrect value (which >>moreover changes through several architectures) while in fact >>'-1' should be reported. >> >>Before the change: >> # cat /sys/class/net/eth0/speed >> 4294967295 >> >>After the change: >> # cat /sys/class/net/eth0/speed >> -1 >> >>Signed-off-by: Michal Privoznik >>--- >> net/core/net-sysfs.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >>diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c >>index 1cac29e..99afdea 100644 >>--- a/net/core/net-sysfs.c >>+++ b/net/core/net-sysfs.c >>@@ -173,7 +173,7 @@ static ssize_t speed_show(struct device *dev, >> if (netif_running(netdev)) { >> struct ethtool_cmd cmd; >> if (!__ethtool_get_settings(netdev, &cmd)) >>- ret = sprintf(buf, fmt_udec, ethtool_cmd_speed(&cmd)); >>+ ret = sprintf(buf, fmt_dec, ethtool_cmd_speed(&cmd)); > >I wonder why this should be signed. What -1 means? What driver reports >this? My first thoughts were exactly this. There is SPEED_UNKOWN (along with _10, _100, _1000 etc.) that's -1, and quite a few drivers use it/set it. I wonder, though, if we should document it or just output "Unknown" instead of -1. > >> } >> rtnl_unlock(); >> return ret; >>-- >>2.0.0 >> >-- >To unsubscribe from this list: send the line "unsubscribe netdev" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/