From patchwork Thu Nov 25 17:20:18 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincent Mailhol X-Patchwork-Id: 12693689 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3D56FC433FE for ; Thu, 25 Nov 2021 17:23:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=P/f1t/xPpifpBm9BBZ1AB5wIIMTwRuyuO323D9eFOss=; b=LaFuNwn79d3O0w e/iyn934/OyeKK2tSYZlsu40EWMNgGMx+oJ/xUGbAza5Z4vaLVN3ZQGnAZeCdC5LBNWBT6q3eaveY ILdFSVQ4Xz/lPpPsjKa1l30NzbOfrFJkjyPbRFeuIhiYs4WZm3PkE6Sfzhs4qOnZZLDxfX70XMcaK prumrIOO2cbPdgljrrPtYUT/ynBulwjR6vPvB5NKJ2nTjcbO5Y88NeQDkpPeRI6K2S6gZNB9NsMVN 22yHwz1wLpb9PuKSDgk7wr66k5W5PxWrWyO0sxMFk8jL9hAIN2GGnjMlsZCdzrRjIbnd8LbwLXCkc yESlJBYD0LjvfLzFCGcg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mqIR5-008MHt-Nc; Thu, 25 Nov 2021 17:21:27 +0000 Received: from smtp09.smtpout.orange.fr ([80.12.242.131] helo=smtp.smtpout.orange.fr) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mqIR1-008MGn-A2 for linux-arm-kernel@lists.infradead.org; Thu, 25 Nov 2021 17:21:25 +0000 Received: from tomoyo.flets-east.jp ([114.149.34.46]) by smtp.orange.fr with ESMTPA id qIQDm0ronE8xTqIQum0kpz; Thu, 25 Nov 2021 18:21:19 +0100 X-ME-Helo: tomoyo.flets-east.jp X-ME-Auth: MDU0YmViZGZmMDIzYiBlMiM2NTczNTRjNWZkZTMwOGRiOGQ4ODf3NWI1ZTMyMzdiODlhOQ== X-ME-Date: Thu, 25 Nov 2021 18:21:19 +0100 X-ME-IP: 114.149.34.46 From: Vincent Mailhol To: Marc Kleine-Budde , linux-can@vger.kernel.org Cc: Oliver Hartkopp , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, Vincent Mailhol , Jimmy Assarsson Subject: [PATCH v2 2/5] can: kvaser_usb: do not increase tx statistics when sending error message frames Date: Fri, 26 Nov 2021 02:20:18 +0900 Message-Id: <20211125172021.976384-3-mailhol.vincent@wanadoo.fr> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211125172021.976384-1-mailhol.vincent@wanadoo.fr> References: <20211125172021.976384-1-mailhol.vincent@wanadoo.fr> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211125_092123_893700_05A01E4C X-CRM114-Status: GOOD ( 14.44 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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 CC: Jimmy Assarsson Signed-off-by: Vincent Mailhol --- .../net/can/usb/kvaser_usb/kvaser_usb_hydra.c | 22 +++++++++++++------ 1 file changed, 15 insertions(+), 7 deletions(-) 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..32fe352dabeb 100644 --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c @@ -1111,8 +1111,10 @@ static void kvaser_usb_hydra_tx_acknowledge(const struct kvaser_usb *dev, { struct kvaser_usb_tx_urb_context *context; struct kvaser_usb_net_priv *priv; + struct can_frame *cf; unsigned long irq_flags; - bool one_shot_fail = false; + int len; + bool one_shot_fail = false, is_err_frame = false; u16 transid = kvaser_usb_hydra_get_cmd_transid(cmd); priv = kvaser_usb_hydra_net_priv_from_cmd(dev, cmd); @@ -1134,21 +1136,27 @@ static void kvaser_usb_hydra_tx_acknowledge(const struct kvaser_usb *dev, } context = &priv->tx_contexts[transid % dev->max_tx_urbs]; - if (!one_shot_fail) { - struct net_device_stats *stats = &priv->netdev->stats; - - stats->tx_packets++; - stats->tx_bytes += can_fd_dlc2len(context->dlc); - } + len = context->dlc; spin_lock_irqsave(&priv->tx_contexts_lock, irq_flags); + cf = (struct can_frame *)priv->can.echo_skb[context->echo_index]->data; + if (cf) + is_err_frame = !!(cf->can_id & CAN_RTR_FLAG); + can_get_echo_skb(priv->netdev, context->echo_index, NULL); context->echo_index = dev->max_tx_urbs; --priv->active_tx_contexts; netif_wake_queue(priv->netdev); spin_unlock_irqrestore(&priv->tx_contexts_lock, irq_flags); + + if (!one_shot_fail && !is_err_frame) { + struct net_device_stats *stats = &priv->netdev->stats; + + stats->tx_packets++; + stats->tx_bytes += len; + } } static void kvaser_usb_hydra_rx_msg_std(const struct kvaser_usb *dev,