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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 3FEA5C433E0 for ; Wed, 27 Jan 2021 09:30:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 101E220780 for ; Wed, 27 Jan 2021 09:30:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235404AbhA0J27 (ORCPT ); Wed, 27 Jan 2021 04:28:59 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:48285 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235253AbhA0JZ6 (ORCPT ); Wed, 27 Jan 2021 04:25:58 -0500 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 1l4h29-0008D7-9L for linux-can@vger.kernel.org; Wed, 27 Jan 2021 10:22:41 +0100 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id 480F35CF113 for ; Wed, 27 Jan 2021 09:22:37 +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 2C2E45CF0E6; Wed, 27 Jan 2021 09:22:32 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id 6e1da509; Wed, 27 Jan 2021 09:22:28 +0000 (UTC) From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org, kernel@pengutronix.de, Marc Kleine-Budde Subject: [net-next 08/12] can: mcp251xfd: mcp251xfd_tx_obj_from_skb(): clean up padding of CAN-FD frames Date: Wed, 27 Jan 2021 10:22:23 +0100 Message-Id: <20210127092227.2775573-9-mkl@pengutronix.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210127092227.2775573-1-mkl@pengutronix.de> References: <20210127092227.2775573-1-mkl@pengutronix.de> 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 CAN-FD frames have only specific frame length (0, 1, 2, 3, 4, 5, 6, 7, 8, 12, 16, 20, 24, 32, 48, 64). A CAN-FD frame provided by user space might not cover the whole CAN-FD frame. To avoid sending garbage over the CAN bus the driver pads the CAN frame with 0x0 (if MCP251XFD_SANITIZE_CAN is activated). This patch cleans up the pad len calculation. Rounding to full u32 brings no benefit, in case of CRC transfers, the hw_tx_obj->data is not aligned to u32 anyway. Link: https://lore.kernel.org/r/20210114153448.1506901-3-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c index 1dbb87c28049..aa992e71d787 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c @@ -2303,7 +2303,7 @@ mcp251xfd_tx_obj_from_skb(const struct mcp251xfd_priv *priv, union mcp251xfd_tx_obj_load_buf *load_buf; u8 dlc; u32 id, flags; - int offset, len; + int pad_len, len; if (cfd->can_id & CAN_EFF_FLAG) { u32 sid, eid; @@ -2351,13 +2351,14 @@ mcp251xfd_tx_obj_from_skb(const struct mcp251xfd_priv *priv, put_unaligned_le32(id, &hw_tx_obj->id); put_unaligned_le32(flags, &hw_tx_obj->flags); - /* Clear data at end of CAN frame */ - offset = round_down(cfd->len, sizeof(u32)); - len = round_up(can_fd_dlc2len(dlc), sizeof(u32)) - offset; - if (MCP251XFD_SANITIZE_CAN && len) - memset(hw_tx_obj->data + offset, 0x0, len); + /* Copy data */ memcpy(hw_tx_obj->data, cfd->data, cfd->len); + /* Clear unused data at end of CAN frame */ + pad_len = can_fd_dlc2len(dlc) - cfd->len; + if (MCP251XFD_SANITIZE_CAN && pad_len) + memset(hw_tx_obj->data + cfd->len, 0x0, pad_len); + /* Number of bytes to be written into the RAM of the controller */ len = sizeof(hw_tx_obj->id) + sizeof(hw_tx_obj->flags); if (MCP251XFD_SANITIZE_CAN) -- 2.29.2