From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Lunn Subject: Re: [Patch RFC net-next] net: usb: r8152: Fix rx_bytes/tx_bytes to include FCS Date: Thu, 18 May 2017 19:33:39 +0200 Message-ID: <20170518173339.GF707@lunn.ch> References: <1495052615-14360-1-git-send-email-andrew@lunn.ch> <286d107e-2380-f8e9-3edf-c949707ea235@gmail.com> <20170518150925.GB707@lunn.ch> <20170518.112256.671702749693595449.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Miller , netdev@vger.kernel.org, hayeswang@realtek.com, mario_limonciello@dell.com To: Florian Fainelli Return-path: Received: from vps0.lunn.ch ([178.209.37.122]:35955 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753623AbdERRdp (ORCPT ); Thu, 18 May 2017 13:33:45 -0400 Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Hi Florian I agree we should define this, and we can add it to Documentation/ABI/testing/sysfs-class-net-statistics > - BQL cares about bytes sent on the wire, so that should not include > pre/appended descriptors nor the FCS (nor the Ethernet preamble), > tx_bytes should be equivalent to that Can you point me at some documentation/code which shows this? pre/appended descriptors i can understand, since it does not make it to the wire. FCS does. Preamble and inter-frame gap also does make it to the wire, and contributes to the overall load on the medium. But i would expect BQL is tolerant to this. We are talking about an error of about 0.26% for a full MTU frame if FCS is included when it should not be. If BQL really does care about not including the FCS, we probably have a lot less to do. People should of audited their code when they added support for BQL :-) Andrew