From patchwork Fri Nov 20 13:33:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Kleine-Budde X-Patchwork-Id: 11920281 X-Patchwork-Delegate: kuba@kernel.org 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=-16.8 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 D9D85C64E75 for ; Fri, 20 Nov 2020 13:33:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F227222BA for ; Fri, 20 Nov 2020 13:33:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728223AbgKTNdc (ORCPT ); Fri, 20 Nov 2020 08:33:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728207AbgKTNdc (ORCPT ); Fri, 20 Nov 2020 08:33:32 -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 C6E73C0613CF for ; Fri, 20 Nov 2020 05:33:31 -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 1kg6XZ-0006Fn-UW; Fri, 20 Nov 2020 14:33:30 +0100 From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org, kernel@pengutronix.de, Marc Kleine-Budde Subject: [net-next 20/25] can: flexcan: flexcan_close(): change order if commands to properly shut down the controller Date: Fri, 20 Nov 2020 14:33:13 +0100 Message-Id: <20201120133318.3428231-21-mkl@pengutronix.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201120133318.3428231-1-mkl@pengutronix.de> References: <20201120133318.3428231-1-mkl@pengutronix.de> MIME-Version: 1.0 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: netdev@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org There haven been reports, that the flexcan_close() soradically hangs during simultanious ifdown, sending of CAN messages and probably open CAN bus: | (__schedule) from [<808bbd34>] (schedule+0x90/0xb8) | (schedule) from [<808bf274>] (schedule_timeout+0x1f8/0x24c) | (schedule_timeout) from [<8016be44>] (msleep+0x18/0x1c) | (msleep) from [<80746a64>] (napi_disable+0x60/0x70) | (napi_disable) from [<8052fdd0>] (flexcan_close+0x2c/0x140) | (flexcan_close) from [<80744930>] (__dev_close_many+0xb8/0xd8) | (__dev_close_many) from [<8074db9c>] (__dev_change_flags+0xd0/0x1a0) | (__dev_change_flags) from [<8074dc84>] (dev_change_flags+0x18/0x48) | (dev_change_flags) from [<80760c24>] (do_setlink+0x44c/0x7b4) | (do_setlink) from [<80761560>] (rtnl_newlink+0x374/0x68c) I was unable to reproduce the issue, but a cleanup of the flexcan close sequence has probably fixed the problem at the reporting user. This patch changes the sequence in flexcan_close() to: - stop the TX queue - disable the interrupts on the chip level and wait via free_irq() synchronously for the interrupt handler to finish - disable RX offload, which disables synchronously NAPI - disable the flexcan on the chip level - free RX offload - disable the transceiver - close the CAN device - disable the clocks Link: https://lore.kernel.org/r/20201119100917.3013281-6-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/flexcan.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index e98368be1669..e85f20d18d67 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -1754,15 +1754,15 @@ static int flexcan_close(struct net_device *dev) struct flexcan_priv *priv = netdev_priv(dev); netif_stop_queue(dev); + flexcan_chip_interrupts_disable(dev); + free_irq(dev->irq, dev); can_rx_offload_disable(&priv->offload); flexcan_chip_stop_disable_on_error(dev); - flexcan_chip_interrupts_disable(dev); can_rx_offload_del(&priv->offload); - free_irq(dev->irq, dev); flexcan_transceiver_disable(priv); - close_candev(dev); + pm_runtime_put(priv->dev); can_led_event(dev, CAN_LED_EVENT_STOP);