From patchwork Fri Dec 3 13:18:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincent Mailhol X-Patchwork-Id: 12655151 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 917E9C433FE for ; Fri, 3 Dec 2021 13:19:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352398AbhLCNWc (ORCPT ); Fri, 3 Dec 2021 08:22:32 -0500 Received: from smtp04.smtpout.orange.fr ([80.12.242.126]:51909 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352267AbhLCNW0 (ORCPT ); Fri, 3 Dec 2021 08:22:26 -0500 Received: from localhost.localdomain ([114.149.34.46]) by smtp.orange.fr with ESMTPA id t8S9mZgOjWUfjt8Somn0zJ; Fri, 03 Dec 2021 14:19:01 +0100 X-ME-Helo: localhost.localdomain X-ME-Auth: MDU0YmViZGZmMDIzYiBlMiM2NTczNTRjNWZkZTMwOGRiOGQ4ODf3NWI1ZTMyMzdiODlhOQ== X-ME-Date: Fri, 03 Dec 2021 14:19:01 +0100 X-ME-IP: 114.149.34.46 From: Vincent Mailhol To: Marc Kleine-Budde , linux-can@vger.kernel.org Cc: Oliver Hartkopp , Jimmy Assarsson , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, Vincent Mailhol Subject: [PATCH v4 2/5] can: kvaser_usb: do not increase tx statistics when sending error message frames Date: Fri, 3 Dec 2021 22:18:05 +0900 Message-Id: <20211203131808.2380042-3-mailhol.vincent@wanadoo.fr> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211203131808.2380042-1-mailhol.vincent@wanadoo.fr> References: <20211203131808.2380042-1-mailhol.vincent@wanadoo.fr> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org The CAN error message frames (i.e. error skb) are an interface specific to socket CAN. The payload of the CAN error message frames does not correspond to any actual data sent on the wire. Only an error flag and a delimiter are transmitted when an error occurs (c.f. ISO 11898-1 section 10.4.4.2 "Error flag"). For this reason, it makes no sense to increment the tx_packets and tx_bytes fields of struct net_device_stats when sending an error message frame because no actual payload will be transmitted on the wire. N.B. Sending error message frames is a very specific feature which, at the moment, is only supported by the Kvaser Hydra hardware. Please refer to [1] for more details on the topic. [1] https://lore.kernel.org/linux-can/CAMZ6RqK0rTNg3u3mBpZOoY51jLZ-et-J01tY6-+mWsM4meVw-A@mail.gmail.com/t/#u Co-developed-by: Jimmy Assarsson Signed-off-by: Jimmy Assarsson Signed-off-by: Vincent Mailhol --- drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c index 3398da323126..75009d38f8e3 100644 --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c @@ -295,6 +295,7 @@ struct kvaser_cmd { #define KVASER_USB_HYDRA_CF_FLAG_OVERRUN BIT(1) #define KVASER_USB_HYDRA_CF_FLAG_REMOTE_FRAME BIT(4) #define KVASER_USB_HYDRA_CF_FLAG_EXTENDED_ID BIT(5) +#define KVASER_USB_HYDRA_CF_FLAG_TX_ACK BIT(6) /* CAN frame flags. Used in ext_rx_can and ext_tx_can */ #define KVASER_USB_HYDRA_CF_FLAG_OSM_NACK BIT(12) #define KVASER_USB_HYDRA_CF_FLAG_ABL BIT(13) @@ -1113,6 +1114,7 @@ static void kvaser_usb_hydra_tx_acknowledge(const struct kvaser_usb *dev, struct kvaser_usb_net_priv *priv; unsigned long irq_flags; bool one_shot_fail = false; + bool is_err_frame = false; u16 transid = kvaser_usb_hydra_get_cmd_transid(cmd); priv = kvaser_usb_hydra_net_priv_from_cmd(dev, cmd); @@ -1131,10 +1133,13 @@ static void kvaser_usb_hydra_tx_acknowledge(const struct kvaser_usb *dev, kvaser_usb_hydra_one_shot_fail(priv, cmd_ext); one_shot_fail = true; } + + is_err_frame = flags & KVASER_USB_HYDRA_CF_FLAG_TX_ACK && + flags & KVASER_USB_HYDRA_CF_FLAG_ERROR_FRAME; } context = &priv->tx_contexts[transid % dev->max_tx_urbs]; - if (!one_shot_fail) { + if (!one_shot_fail && !is_err_frame) { struct net_device_stats *stats = &priv->netdev->stats; stats->tx_packets++;