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=-6.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 86544C433E9 for ; Thu, 18 Feb 2021 21:55:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 44B4264E38 for ; Thu, 18 Feb 2021 21:55:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229655AbhBRVzU (ORCPT ); Thu, 18 Feb 2021 16:55:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229577AbhBRVzT (ORCPT ); Thu, 18 Feb 2021 16:55:19 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99B1DC061574 for ; Thu, 18 Feb 2021 13:54:39 -0800 (PST) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lCrFu-0000kN-73 for linux-can@vger.kernel.org; Thu, 18 Feb 2021 22:54:38 +0100 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id 14A835E44E7 for ; Thu, 18 Feb 2021 21:54:37 +0000 (UTC) Received: from hardanger.blackshift.org (unknown [172.20.34.65]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by bjornoya.blackshift.org (Postfix) with ESMTPS id 991085E44E2; Thu, 18 Feb 2021 21:54:36 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id 7e134010; Thu, 18 Feb 2021 21:54:35 +0000 (UTC) From: Marc Kleine-Budde To: linux-can@vger.kernel.org Cc: kernel@pengutronix.de Subject: [RFC] can: isotp TX-path cleanups Date: Thu, 18 Feb 2021 22:54:32 +0100 Message-Id: <20210218215434.1708249-1-mkl@pengutronix.de> X-Mailer: git-send-email 2.30.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-can@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org Hello we've noticed that "candump -x" on normal CAN ISO-TP traffic shows: | (2021-02-18 14:52:51.643904) ca0 TX B E 713 [8] 20 0D 0E 0F AA AA AA AA Note here the "B" and "E" flags are set. Another possibility is to use skb_put_zero() instead of skb_put(), but with a bigger overhead. A 3. option is to only memset() the non-data part of the struct canfd_frame. regards, Marc