From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f195.google.com (mail-pf1-f195.google.com [209.85.210.195]) by dpdk.org (Postfix) with ESMTP id 64AC32BF9 for ; Tue, 11 Sep 2018 23:52:56 +0200 (CEST) Received: by mail-pf1-f195.google.com with SMTP id i26-v6so12864112pfo.12 for ; Tue, 11 Sep 2018 14:52:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=F2CZZaEqLIYDN+K4jvvGmQzpb/RD16r2KcrAWL3Jb0I=; b=XNOPU7/4B1hiwctvgArlTIqCEgI3IFh+SPBOPXmiDQUehaBfn5rMhP/u9SZEY72t0e 6CgMgt+t/T9H5C8wyp7eUBfLVvxMIYlwqeui4Qw7Pd24aYGxS1RoToB1RWmAJPpHa8pE 5o/z9ff6+1hTbfVidDPUzxYkhbwmxWWq1o0htD6+yexpM9G4Aj2q7d2pnlCDCaEU9x5O CauZecd8qLEnrRbt8Pqw49gyz9VOfjBn3rGCV2rwKAQ5W1YDYiLe9IcIzcYUthWiGYqe p/uHpv0GX7ln+jjKSE1U1vysaPubNgGFOnCvDIySvg1iXIvSgO4ePHa+op5tNptowbQj OFIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=F2CZZaEqLIYDN+K4jvvGmQzpb/RD16r2KcrAWL3Jb0I=; b=tUGUZCRaJIODUZ4H9AqDa+aKV9KUiAGFHp3R+UBqt7jwNMj+MdHoR2kP2nBS06XQgr 1Tl5h3UJSpuPi7GKAgUhOvTuzR6bVlPdt62Axvc5PWU2CgHYtM2b3zRGm7fQzBY/53RM qDaiBPFXmUIhY+RtVecAq0ZmD+muRl1a8JpDQ/zauGAR62/55F6y5dMbUiKStgxizEFN t/aagTPZrhTlI/RXa8nucIfefZf8uRsgVRl2JkRyvsbjDdWqHYs7AKBYkFpmnVqNxyuJ jh9KyqZqMp0UU/t6OkRFWdH5w0yzAM+ibgr9iwawrU/4OrCVu1yQGer9+3g57nQ5a+1a 1aXw== X-Gm-Message-State: APzg51BHCdmKWAcccvF9jR3vzGnw5pOVYwKl6B20892CTbJmYkQtfzFZ ffZV5me3PivQ6DUDQDGptadkSQ== X-Google-Smtp-Source: ANB0VdaigkHwPaKihthRnK26TlGOXbsiZq7FYdeHflhgR5gj1vixgUuMb7kbc0eOV1ioLSigp/voMA== X-Received: by 2002:a63:c807:: with SMTP id z7-v6mr29761124pgg.77.1536702775470; Tue, 11 Sep 2018 14:52:55 -0700 (PDT) Received: from xeon-e3 (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id d66-v6sm30036427pfd.121.2018.09.11.14.52.55 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 11 Sep 2018 14:52:55 -0700 (PDT) Date: Tue, 11 Sep 2018 14:52:48 -0700 From: Stephen Hemminger To: Dan Gora Cc: Igor Ryzhov , Ferruh Yigit , dev@dpdk.org Message-ID: <20180911145248.7512abd1@xeon-e3> In-Reply-To: References: <20180628224513.18391-1-dg@adax.com> <20180629015508.26599-1-dg@adax.com> <20180629015508.26599-11-dg@adax.com> <20180829085410.4411c07e@xeon-e3> <20180829150014.0ae59128@xeon-e3> <20180829161043.11bb2434@xeon-e3> <20180830150911.6b0e7901@xeon-e3> <20180905135751.74f6c14b@shemminger-XPS-13-9360> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v2 10/10] kni: add API to set link status on kernel interface X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Sep 2018 21:52:56 -0000 On Tue, 11 Sep 2018 18:45:49 -0300 Dan Gora wrote: > Hi All, > > So I implemented the "write to /sys/devices/virtual/net/*/carrier" > method to change the link status, but there is one more minor thing > that I wanted to point out about this approach. The problem is that > you cannot read or write the '/sys/devices/virtual/net/*/carrier' file > while the interface is marked 'down'. This means that link status > changes can only be performed by the DPDK application while the > interface is in the "up" state. With the ioctl method, you can change > the carrier state at pretty much any time. > > Is this a problem? It's not a huge one, I guess, but it is something > else to consider. > > Please let me know what you all think. > > thanks > dan The carrier state has no meaning when device is down, at least for physical devices. Because often the PHY is powered off when the device is marked down.