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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 73575C7618B for ; Wed, 24 Jul 2019 13:03:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 512BA21901 for ; Wed, 24 Jul 2019 13:03:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387447AbfGXNDh (ORCPT ); Wed, 24 Jul 2019 09:03:37 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:51051 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727348AbfGXNDe (ORCPT ); Wed, 24 Jul 2019 09:03:34 -0400 Received: from heimdall.vpn.pengutronix.de ([2001:67c:670:205:1d::14] helo=blackshift.org) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1hqGvb-0006gK-C9; Wed, 24 Jul 2019 15:03:31 +0200 From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, linux-can@vger.kernel.org, kernel@pengutronix.de, Joakim Zhang , Marc Kleine-Budde , linux-stable Subject: [PATCH 5/7] can: flexcan: fix stop mode acknowledgment Date: Wed, 24 Jul 2019 15:03:20 +0200 Message-Id: <20190724130322.31702-6-mkl@pengutronix.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190724130322.31702-1-mkl@pengutronix.de> References: <20190724130322.31702-1-mkl@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:205:1d::14 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 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Joakim Zhang To enter stop mode, the CPU should manually assert a global Stop Mode request and check the acknowledgment asserted by FlexCAN. The CPU must only consider the FlexCAN in stop mode when both request and acknowledgment conditions are satisfied. Fixes: de3578c198c6 ("can: flexcan: add self wakeup support") Reported-by: Marc Kleine-Budde Signed-off-by: Joakim Zhang Cc: linux-stable # >= v5.0 Signed-off-by: Marc Kleine-Budde --- drivers/net/can/flexcan.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index 33ce45d51e15..fcec8bcb53d6 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -400,9 +400,10 @@ static void flexcan_enable_wakeup_irq(struct flexcan_priv *priv, bool enable) priv->write(reg_mcr, ®s->mcr); } -static inline void flexcan_enter_stop_mode(struct flexcan_priv *priv) +static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv) { struct flexcan_regs __iomem *regs = priv->regs; + unsigned int ackval; u32 reg_mcr; reg_mcr = priv->read(®s->mcr); @@ -412,20 +413,37 @@ static inline void flexcan_enter_stop_mode(struct flexcan_priv *priv) /* enable stop request */ regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr, 1 << priv->stm.req_bit, 1 << priv->stm.req_bit); + + /* get stop acknowledgment */ + if (regmap_read_poll_timeout(priv->stm.gpr, priv->stm.ack_gpr, + ackval, ackval & (1 << priv->stm.ack_bit), + 0, FLEXCAN_TIMEOUT_US)) + return -ETIMEDOUT; + + return 0; } -static inline void flexcan_exit_stop_mode(struct flexcan_priv *priv) +static inline int flexcan_exit_stop_mode(struct flexcan_priv *priv) { struct flexcan_regs __iomem *regs = priv->regs; + unsigned int ackval; u32 reg_mcr; /* remove stop request */ regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr, 1 << priv->stm.req_bit, 0); + /* get stop acknowledgment */ + if (regmap_read_poll_timeout(priv->stm.gpr, priv->stm.ack_gpr, + ackval, !(ackval & (1 << priv->stm.ack_bit)), + 0, FLEXCAN_TIMEOUT_US)) + return -ETIMEDOUT; + reg_mcr = priv->read(®s->mcr); reg_mcr &= ~FLEXCAN_MCR_SLF_WAK; priv->write(reg_mcr, ®s->mcr); + + return 0; } static inline void flexcan_error_irq_enable(const struct flexcan_priv *priv) @@ -1614,7 +1632,9 @@ static int __maybe_unused flexcan_suspend(struct device *device) */ if (device_may_wakeup(device)) { enable_irq_wake(dev->irq); - flexcan_enter_stop_mode(priv); + err = flexcan_enter_stop_mode(priv); + if (err) + return err; } else { err = flexcan_chip_disable(priv); if (err) @@ -1664,10 +1684,13 @@ static int __maybe_unused flexcan_noirq_resume(struct device *device) { struct net_device *dev = dev_get_drvdata(device); struct flexcan_priv *priv = netdev_priv(dev); + int err; if (netif_running(dev) && device_may_wakeup(device)) { flexcan_enable_wakeup_irq(priv, false); - flexcan_exit_stop_mode(priv); + err = flexcan_exit_stop_mode(priv); + if (err) + return err; } return 0; -- 2.20.1