From nobody Thu Oct 2 23:50:49 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 C911D35AAC5 for ; Tue, 9 Sep 2025 17:53:46 +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=1757440431; cv=none; b=KxDWO1A1gSPL6gS/tAaiF8tytGamrTF4qXiD1ug4kpV6rviGaLBzlicpWOyPWdp5YUpeWcNHBnIEQyl5yA2+e7q1C6bkUhSFcGuFXS499axQJLrZGyuyrVrezhRmn24dSsVWPL5T7j+K5t7R+EQxpgxfGGtiAjXP+nEcslKgeMU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757440431; c=relaxed/simple; bh=51tr54JnhZakrnoQo/rT0O+jc3YyZDKaoBKsy55zljc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=aMPmTB4/1IvkuvKgNDOkibYSky3PuIArDmRmzOCgIbTUzCTNXsD0Zws/OgToHvSdtisWgvSlhhFsLvsMmvhvxEdV0ftqDBq35jwBa8LcV2mBbX5WKeLQ7BKCPzOQOGfoa54eBGu2mVZIZjuyXIYDzra5I5L4Ha3dOz+rCn3tClI= 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 1uw2XI-0006ir-Uc for linux-kernel@vger.kernel.org; Tue, 09 Sep 2025 19:53:44 +0200 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 1uw2XI-000Sbk-0q for linux-kernel@vger.kernel.org; Tue, 09 Sep 2025 19:53:44 +0200 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id EEBE246A3D6 for ; Tue, 09 Sep 2025 17:53:43 +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 x25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by bjornoya.blackshift.org (Postfix) with ESMTPS id 4B5BD46A39D; Tue, 09 Sep 2025 17:53:41 +0000 (UTC) Received: from hardanger.blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id 2ce24846; Tue, 9 Sep 2025 17:53:40 +0000 (UTC) From: Marc Kleine-Budde Date: Tue, 09 Sep 2025 19:53:19 +0200 Subject: [PATCH v2 3/7] can: m_can: m_can_handle_state_errors(): fix CAN state transition to Error Active 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: <20250909-m_can-fix-state-handling-v2-3-af9fa240b68a@pengutronix.de> References: <20250909-m_can-fix-state-handling-v2-0-af9fa240b68a@pengutronix.de> In-Reply-To: <20250909-m_can-fix-state-handling-v2-0-af9fa240b68a@pengutronix.de> To: Chandrasekar Ramakrishnan , Vincent Mailhol , Patrik Flykt , Dong Aisheng , Varka Bhadram , Wu Bo , Markus Schneider-Pargmann , Philipp Zabel Cc: linux-can@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de, Marc Kleine-Budde X-Mailer: b4 0.15-dev-e44bb X-Developer-Signature: v=1; a=openpgp-sha256; l=3774; i=mkl@pengutronix.de; h=from:subject:message-id; bh=51tr54JnhZakrnoQo/rT0O+jc3YyZDKaoBKsy55zljc=; b=owEBbQGS/pANAwAKAQx0Zd/5kJGcAcsmYgBowGmbq9JfvnPrkj4xY32meikqqA8cz29Dpo5b3 NbTPAhd3HiJATMEAAEKAB0WIQSf+wzYr2eoX/wVbPMMdGXf+ZCRnAUCaMBpmwAKCRAMdGXf+ZCR nIfrB/9Vp+XgN8RRlTxXeO2f0OJSZzTQJITFK/q9XVUEHqnVTUSudtRUhiCfrFSdnJ+tImmLKrz toKTBrYpmyAUHGiMAwt65f/CywS4qAL9vDw/D3QddbY4tVAR4ZpjxIuxLo1ECa1S6VGQrU0Y9B0 u9edz5VUQa9vN3pKU8GO+lihrkZuECJnU4YmylbVtAErLUwcU6CbY8Hfy4igDhtzzSQfG6af5NN Tjm1NWI38y+1rEKXB2PmJzFlPpx2P4JZvAayUNSU8jXsoz93Hm7W7w2/81Glrr4KvZjc9ohIBfd g7dGpfheJeTChAwL7AhE9zYRDX6TejIDJulA6L1QfAeVnpUu 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 The CAN Error State is determined by the receive and transmit error counters. The CAN error counters decrease when reception/transmission is successful, so that a status transition back to the Error Active status is possible. This transition is not handled by m_can_handle_state_errors(). Add the missing detection of the Error Active state to m_can_handle_state_errors() and extend the handling of this state in m_can_handle_state_change(). Fixes: e0d1f4816f2a ("can: m_can: add Bosch M_CAN controller support") Fixes: cd0d83eab2e0 ("can: m_can: m_can_handle_state_change(): fix state ch= ange") Signed-off-by: Marc Kleine-Budde Reviewed-by: Markus Schneider-Pargmann --- drivers/net/can/m_can/m_can.c | 55 ++++++++++++++++++++++++++-------------= ---- 1 file changed, 33 insertions(+), 22 deletions(-) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index 16b38e6c3985..3edf01b098a4 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -812,6 +812,9 @@ static int m_can_handle_state_change(struct net_device = *dev, u32 timestamp =3D 0; =20 switch (new_state) { + case CAN_STATE_ERROR_ACTIVE: + cdev->can.state =3D CAN_STATE_ERROR_ACTIVE; + break; case CAN_STATE_ERROR_WARNING: /* error warning state */ cdev->can.can_stats.error_warning++; @@ -841,6 +844,12 @@ static int m_can_handle_state_change(struct net_device= *dev, __m_can_get_berr_counter(dev, &bec); =20 switch (new_state) { + case CAN_STATE_ERROR_ACTIVE: + cf->can_id |=3D CAN_ERR_CRTL | CAN_ERR_CNT; + cf->data[1] =3D CAN_ERR_CRTL_ACTIVE; + cf->data[6] =3D bec.txerr; + cf->data[7] =3D bec.rxerr; + break; case CAN_STATE_ERROR_WARNING: /* error warning state */ cf->can_id |=3D CAN_ERR_CRTL | CAN_ERR_CNT; @@ -877,30 +886,33 @@ static int m_can_handle_state_change(struct net_devic= e *dev, return 1; } =20 -static int m_can_handle_state_errors(struct net_device *dev, u32 psr) +static enum can_state +m_can_state_get_by_psr(struct m_can_classdev *cdev) +{ + u32 reg_psr; + + reg_psr =3D m_can_read(cdev, M_CAN_PSR); + + if (reg_psr & PSR_BO) + return CAN_STATE_BUS_OFF; + if (reg_psr & PSR_EP) + return CAN_STATE_ERROR_PASSIVE; + if (reg_psr & PSR_EW) + return CAN_STATE_ERROR_WARNING; + + return CAN_STATE_ERROR_ACTIVE; +} + +static int m_can_handle_state_errors(struct net_device *dev) { struct m_can_classdev *cdev =3D netdev_priv(dev); - int work_done =3D 0; + enum can_state new_state; =20 - if (psr & PSR_EW && cdev->can.state !=3D CAN_STATE_ERROR_WARNING) { - netdev_dbg(dev, "entered error warning state\n"); - work_done +=3D m_can_handle_state_change(dev, - CAN_STATE_ERROR_WARNING); - } + new_state =3D m_can_state_get_by_psr(cdev); + if (new_state =3D=3D cdev->can.state) + return 0; =20 - if (psr & PSR_EP && cdev->can.state !=3D CAN_STATE_ERROR_PASSIVE) { - netdev_dbg(dev, "entered error passive state\n"); - work_done +=3D m_can_handle_state_change(dev, - CAN_STATE_ERROR_PASSIVE); - } - - if (psr & PSR_BO && cdev->can.state !=3D CAN_STATE_BUS_OFF) { - netdev_dbg(dev, "entered error bus off state\n"); - work_done +=3D m_can_handle_state_change(dev, - CAN_STATE_BUS_OFF); - } - - return work_done; + return m_can_handle_state_change(dev, new_state); } =20 static void m_can_handle_other_err(struct net_device *dev, u32 irqstatus) @@ -1031,8 +1043,7 @@ static int m_can_rx_handler(struct net_device *dev, i= nt quota, u32 irqstatus) } =20 if (irqstatus & IR_ERR_STATE) - work_done +=3D m_can_handle_state_errors(dev, - m_can_read(cdev, M_CAN_PSR)); + work_done +=3D m_can_handle_state_errors(dev); =20 if (irqstatus & IR_ERR_BUS_30X) work_done +=3D m_can_handle_bus_errors(dev, irqstatus, --=20 2.51.0