From patchwork Sun Jan 10 10:35:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincent Mailhol X-Patchwork-Id: 12009009 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=-11.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 3C3D5C433E6 for ; Sun, 10 Jan 2021 10:38:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0F28123A58 for ; Sun, 10 Jan 2021 10:38:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726390AbhAJKiZ (ORCPT ); Sun, 10 Jan 2021 05:38:25 -0500 Received: from smtp05.smtpout.orange.fr ([80.12.242.127]:53563 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726142AbhAJKiZ (ORCPT ); Sun, 10 Jan 2021 05:38:25 -0500 Received: from localhost.localdomain ([153.202.107.157]) by mwinf5d52 with ME id EycA2400E3PnFJp03ycdtu; Sun, 10 Jan 2021 11:36:41 +0100 X-ME-Helo: localhost.localdomain X-ME-Auth: bWFpbGhvbC52aW5jZW50QHdhbmFkb28uZnI= X-ME-Date: Sun, 10 Jan 2021 11:36:41 +0100 X-ME-IP: 153.202.107.157 From: Vincent Mailhol To: Marc Kleine-Budde , linux-can@vger.kernel.org Cc: Vincent Mailhol , Wolfgang Grandegger , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org (open list:NETWORKING DRIVERS), linux-kernel@vger.kernel.org (open list) Subject: [PATCH 0/1] Add software TX timestamps to the CAN devices Date: Sun, 10 Jan 2021 19:35:25 +0900 Message-Id: <20210110103526.61047-1-mailhol.vincent@wanadoo.fr> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org With the ongoing work to add BQL to Socket CAN, I figured out that it would be nice to have an easy way to mesure the latency. And one easy way to do so it to check the round trip time of the packet by doing the difference between the software rx timestamp and the software tx timestamp. rx timestamps are already available. This patch gives the missing piece: add a tx software timestamp feature to the CAN devices. Of course, the tx software timestamp might also be used for other purposes such as performance measurements of the different queuing disciplines (e.g. by checking the difference between the kernel tx software timestamp and the userland tx software timestamp). Vincent Mailhol (1): can: dev: add software tx timestamps drivers/net/can/dev.c | 2 ++ 1 file changed, 2 insertions(+)