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 A1EE835CED2 for ; Tue, 9 Sep 2025 17:53:49 +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=1757440432; cv=none; b=D8LVgTxCbWT4k9581mHBKyJ2l2lr9OPgd54Yc3E+66WxbBLBHC8sD66xZBcDnHmlsy9nD2kVuekAtKaPi45/rzCX69zyUkYlo0hR7+/UITrCYYtlIAbMGgLDnxmVAC6tatQCqxCN+dt1E2J+NPvrpsdYdEi24SN4OEcU5BqhbOk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757440432; c=relaxed/simple; bh=ko64cZOLzYITscm15DfY3Ixy65JrBPp9GIDXs4/Gvns=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=hK+4EwOzClA7ZTkJjBXXKDtV9wy/EF/La6kElpgHniRpvzm1MEaQ5ICUlCnf77LVdTkosOHyFVLJPaHw5Y9bOm9DqUw2pgVG07R4aKOg4oSy6wA/kGq+XQQfP1BO3AVAvsTB4Y6ZvwO4nqdu0sg+oBrbRGCcZPgzV9LA4rB57qI= 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 1uw2XM-0006s8-3S for linux-kernel@vger.kernel.org; Tue, 09 Sep 2025 19:53:48 +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 1uw2XL-000SeM-0F for linux-kernel@vger.kernel.org; Tue, 09 Sep 2025 19:53:47 +0200 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id BDD2546A3FD for ; Tue, 09 Sep 2025 17:53:46 +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 99A0146A3A5; Tue, 09 Sep 2025 17:53:41 +0000 (UTC) Received: from hardanger.blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id dc66c1a5; Tue, 9 Sep 2025 17:53:40 +0000 (UTC) From: Marc Kleine-Budde Date: Tue, 09 Sep 2025 19:53:22 +0200 Subject: [PATCH v2 6/7] can: m_can: m_can_get_berr_counter(): don't wake up controller if interface is down 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-v2-6-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=892; i=mkl@pengutronix.de; h=from:subject:message-id; bh=ko64cZOLzYITscm15DfY3Ixy65JrBPp9GIDXs4/Gvns=; b=owEBbQGS/pANAwAKAQx0Zd/5kJGcAcsmYgBowGmg/eQnGKIR7XS+zOvvbAM9ewU01ERbDaJvm GAKPTqj2KaJATMEAAEKAB0WIQSf+wzYr2eoX/wVbPMMdGXf+ZCRnAUCaMBpoAAKCRAMdGXf+ZCR nJWaCACoJVbnMAqYbEb2rre1Jkg9jtkal9sPN1FbF3Xk1lKCwsgbsXUJ4RHRpswAJhoZPyN5rct 2Xjv/F1jLv1WPoXiy7czmK3zWqBv2B1a8Am0ddSX2FKBSlbFwslO9cQoe6MwTduxFw8f6qapyb8 rOO77psS88wv33XlCYqVsd5+TlAN0/aHx/l8KeUyw3tGse+jAd0TpmmK4d5sIubDemNLa5c82g3 Yyc3pn78R26kVEfuxcY8bYPA5/ebGdI2jCCdE6fHibEvP/R3V+hDd/PL2N1vKWpurey7eikuOKH 9JFgxHWJUrHSVdLEeh0uL3FGoe+hMMhTlWqxU9fTPJabtUNy 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 If the interface is down, the CAN controller might be powered down, the clock disabled, and/or it's external reset asserted. Don't wake up the controller to read the CAN bus error counters, if the interface is down. Signed-off-by: Marc Kleine-Budde --- drivers/net/can/m_can/m_can.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index d44e348f2417..9528af8500af 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -790,6 +790,10 @@ static int m_can_get_berr_counter(const struct net_dev= ice *dev, struct m_can_classdev *cdev =3D netdev_priv(dev); int err; =20 + /* Avoid waking up the controller if the interface is down */ + if (!(dev->flags & IFF_UP)) + return 0; + err =3D m_can_clk_start(cdev); if (err) return err; --=20 2.51.0