From nobody Mon Dec 1 23:03:14 2025 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 249C42FD69F for ; Wed, 26 Nov 2025 10:17:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764152224; cv=none; b=Kmkx+RoEY6mRDPBUn/iym7MrPH8GkkqoO6/hpsaYJO8605/rmwBr2UPH1EPbtUamPvj5kcDuhB9tqBGfV5GH3ou2feVSItckQvMe7bW4HL1fJfx/6aU8nXqdWjZTqCh+Kxp0Vg7Re391MHITihdFmmTw7120bI04FLjue4Ovq6o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764152224; c=relaxed/simple; bh=nairXQ9rIPW+imcD7BjKitK2BHOOiL01JpUuX5MLgc8=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=H9xnXRitDGz91OGghhecgMUmcTLmhQSNFlKOztQybGMzecomaSdJAUTwuhPMfiyqfF0wD1E7CZSyqH+GFrdZLLrQhTfB5+wXXodvelsv2nTfr6hTzqxvQaxhIAaJF0VoOony46PYQtZcuE45cs6PEk51ZbQVMAGoN6mFhP4TjMI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1vOCZv-0000Qx-H4; Wed, 26 Nov 2025 11:16:51 +0100 Received: from moin.white.stw.pengutronix.de ([2a0a:edc0:0:b01:1d::7b] helo=bjornoya.blackshift.org) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1vOCZv-002aSl-0Q; Wed, 26 Nov 2025 11:16:51 +0100 Received: from hardanger.blackshift.org (p54b152ce.dip0.t-ipconnect.de [84.177.82.206]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: mkl-all@blackshift.org) by smtp.blackshift.org (Postfix) with ESMTPSA id DAA584A88D8; Wed, 26 Nov 2025 10:16:50 +0000 (UTC) From: Marc Kleine-Budde Date: Wed, 26 Nov 2025 11:16:08 +0100 Subject: [PATCH can-next v8 07/17] can: dev: can_dev_dropped_skb: drop CC/FD frames in CANXL-only mode Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20251126-canxl-v8-7-e7e3eb74f889@pengutronix.de> References: <20251126-canxl-v8-0-e7e3eb74f889@pengutronix.de> In-Reply-To: <20251126-canxl-v8-0-e7e3eb74f889@pengutronix.de> To: Marc Kleine-Budde , Vincent Mailhol , Oliver Hartkopp Cc: kernel@pengutronix.de, linux-can@vger.kernel.org, linux-kernel@vger.kernel.org, =?utf-8?q?St=C3=A9phane_Grosjean?= X-Mailer: b4 0.15-dev-a6db3 X-Developer-Signature: v=1; a=openpgp-sha256; l=2650; i=mkl@pengutronix.de; h=from:subject:message-id; bh=+xs9GjCtM7BOsuxCHzohc9NNywqTNpj79PW2gV2riAI=; b=owEBbQGS/pANAwAKAQx0Zd/5kJGcAcsmYgBpJtN+zZfLLPlMTzDKzV20ZAJ0kIkZrI3lIRS8x TRMuOoVHMmJATMEAAEKAB0WIQSf+wzYr2eoX/wVbPMMdGXf+ZCRnAUCaSbTfgAKCRAMdGXf+ZCR nJPuB/sFg0o1dDoDJA2av5pFNPf57YuKrcX4DrUNhGigx950d9v1Uz5aflCDKUzoE4RzgcjtrY/ 1PzpWiYT+juf71gqFziQutyda5/47lhjGopd/3zSObtwIdfob/+BUesHSMN4gauCdkW7i6B7fFj +Mmbh1MxMvtf0Yfwg5b5t2xNUpgRevyM3QbOTGAReotaHQRH+anHJMXOINo2lK4fjpKyO27JG2G iWg/yM0okLABdMLHsc4jySTi8DtSKaC0Y+xa/j4/reDkZKaSDtF6yh6JvvQKmhRIuq3Mgjjfwgz Q9dhGN3YafivRo0N2XGwfMqoJStUAb7+NofZc5+QJwJ+/IhG X-Developer-Key: i=mkl@pengutronix.de; a=openpgp; fpr=C1400BA0B3989E6FBC7D5B5C2B5EE211C58AEA54 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org From: Oliver Hartkopp The error-signalling (ES) is a mandatory functionality for CAN CC and CAN FD to report CAN frame format violations by sending an error-frame signal on the bus. A so-called 'mixed-mode' is intended to have (XL-tolerant) CAN FD nodes and CAN XL nodes on one CAN segment, where the FD-controllers can talk CC/FD and the XL-controllers can talk CC/FD/XL. This mixed-mode utilizes the error-signalling for sending CC/FD/XL frames. The CANXL-only mode disables the error-signalling in the CAN XL controller. This mode does not allow CC/FD frames to be sent but additionally offers a CAN XL transceiver mode switching (TMS). Configured with CAN_CTRLMODE_FD and CAN_CTRLMODE_XL this leads to: FD=3D0 XL=3D0 CC-only mode (ES=3D1) FD=3D1 XL=3D0 FD/CC mixed-mode (ES=3D1) FD=3D1 XL=3D1 XL/FD/CC mixed-mode (ES=3D1) FD=3D0 XL=3D1 XL-only mode (ES=3D0, TMS optional) The helper function can_dev_in_xl_only_mode() determines the required value to disable error signalling in the CAN XL controller. Signed-off-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- include/linux/can/dev.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index f15879bd818d..52c8be5c160e 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -135,6 +135,19 @@ void can_bus_off(struct net_device *dev); const char *can_get_state_str(const enum can_state state); const char *can_get_ctrlmode_str(u32 ctrlmode); =20 +static inline bool can_dev_in_xl_only_mode(struct can_priv *priv) +{ + const u32 mixed_mode =3D CAN_CTRLMODE_FD | CAN_CTRLMODE_XL; + + /* When CAN XL is enabled but FD is disabled we are running in + * the so-called 'CANXL-only mode' where the error signalling is + * disabled. This helper function determines the required value + * to disable error signalling in the CAN XL controller. + * The so-called CC/FD/XL 'mixed mode' requires error signalling. + */ + return ((priv->ctrlmode & mixed_mode) =3D=3D CAN_CTRLMODE_XL); +} + /* drop skb if it does not contain a valid CAN frame for sending */ static inline bool can_dev_dropped_skb(struct net_device *dev, struct sk_b= uff *skb) { @@ -153,6 +166,12 @@ static inline bool can_dev_dropped_skb(struct net_devi= ce *dev, struct sk_buff *s goto invalid_skb; } =20 + if (can_dev_in_xl_only_mode(priv) && !can_is_canxl_skb(skb)) { + netdev_info_once(dev, + "Error signaling is disabled, dropping skb\n"); + goto invalid_skb; + } + return can_dropped_invalid_skb(dev, skb); =20 invalid_skb: --=20 2.51.0