From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D676DC5519F for ; Wed, 18 Nov 2020 15:01:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E72924728 for ; Wed, 18 Nov 2020 15:01:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726736AbgKRPBw (ORCPT ); Wed, 18 Nov 2020 10:01:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726501AbgKRPBw (ORCPT ); Wed, 18 Nov 2020 10:01:52 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF047C0613D4 for ; Wed, 18 Nov 2020 07:01:51 -0800 (PST) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=blackshift.org) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1kfOxx-0003NS-PQ; Wed, 18 Nov 2020 16:01:49 +0100 From: Marc Kleine-Budde To: linux-can@vger.kernel.org Cc: Joakim Zhang , kernel@pengutronix.de, Marc Kleine-Budde Subject: [PATCH] can: flexcan: flexcan_chip_start(): fix erroneous flexcan_transceiver_enable() during bus-off recovery Date: Wed, 18 Nov 2020 16:01:48 +0100 Message-Id: <20201118150148.2664024-1-mkl@pengutronix.de> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-can@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org If the CAN controller goes into bus off, the do_set_mode() callback with CAN_MODE_START can be used to recover the controller, which then calls flexcan_chip_start(). If configured, this is done automatically by the framework or manually by the user. In flexcan_chip_start() there is an explicit call to flexcan_transceiver_enable(), which does a regulator_enable() on the transceiver regulator. This results in a net usage counter increase, as there is no corresponding flexcan_transceiver_disable() in the bus off code path. This further leads to the transceiver stuck enabled, even if the CAN interface is shut down. To fix this problem the flexcan_transceiver_enable()/flexcan_transceiver_disable() are moved out of flexcan_chip_start()/flexcan_chip_stop() into flexcan_open()/flexcan_close(). Fixes: e955cead0311 ("CAN: Add Flexcan CAN controller driver") Signed-off-by: Marc Kleine-Budde --- drivers/net/can/flexcan.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index d6a9cf0e9b60..99e5f272205d 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -1567,14 +1567,10 @@ static int flexcan_chip_start(struct net_device *dev) priv->write(reg_ctrl2, ®s->ctrl2); } - err = flexcan_transceiver_enable(priv); - if (err) - goto out_chip_disable; - /* synchronize with the can bus */ err = flexcan_chip_unfreeze(priv); if (err) - goto out_transceiver_disable; + goto out_chip_disable; priv->can.state = CAN_STATE_ERROR_ACTIVE; @@ -1592,8 +1588,6 @@ static int flexcan_chip_start(struct net_device *dev) return 0; - out_transceiver_disable: - flexcan_transceiver_disable(priv); out_chip_disable: flexcan_chip_disable(priv); return err; @@ -1623,7 +1617,6 @@ static int __flexcan_chip_stop(struct net_device *dev, bool disable_on_error) priv->write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL, ®s->ctrl); - flexcan_transceiver_disable(priv); priv->can.state = CAN_STATE_STOPPED; return 0; @@ -1665,10 +1658,14 @@ static int flexcan_open(struct net_device *dev) if (err) goto out_runtime_put; - err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev); + err = flexcan_transceiver_enable(priv); if (err) goto out_close; + err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev); + if (err) + goto out_transceiver_disable; + if (priv->can.ctrlmode & CAN_CTRLMODE_FD) priv->mb_size = sizeof(struct flexcan_mb) + CANFD_MAX_DLEN; else @@ -1720,6 +1717,8 @@ static int flexcan_open(struct net_device *dev) can_rx_offload_del(&priv->offload); out_free_irq: free_irq(dev->irq, dev); + out_transceiver_disable: + flexcan_transceiver_disable(priv); out_close: close_candev(dev); out_runtime_put: @@ -1738,6 +1737,7 @@ static int flexcan_close(struct net_device *dev) can_rx_offload_del(&priv->offload); free_irq(dev->irq, dev); + flexcan_transceiver_disable(priv); close_candev(dev); pm_runtime_put(priv->dev); -- 2.29.2