From ba569fb07a7e9e9b71e9282e27e993ba859295c2 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Wed, 6 Aug 2025 17:46:32 +0200 Subject: can: m_can: m_can_plat_remove(): add missing pm_runtime_disable() Commit 227619c3ff7c ("can: m_can: move runtime PM enable/disable to m_can_platform") moved the PM runtime enable from the m_can core driver into the m_can_platform. That patch forgot to move the pm_runtime_disable() to m_can_plat_remove(), so that unloading the m_can_platform driver causes an "Unbalanced pm_runtime_enable!" error message. Add the missing pm_runtime_disable() to m_can_plat_remove() to fix the problem. Cc: Patrik Flykt Fixes: 227619c3ff7c ("can: m_can: move runtime PM enable/disable to m_can_platform") Reviewed-by: Markus Schneider-Pargmann Link: https://patch.msgid.link/20250929-m_can-fix-state-handling-v4-1-682b49b49d9a@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/m_can/m_can_platform.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c index b832566efda0..057eaa7b8b4b 100644 --- a/drivers/net/can/m_can/m_can_platform.c +++ b/drivers/net/can/m_can/m_can_platform.c @@ -180,7 +180,7 @@ static void m_can_plat_remove(struct platform_device *pdev) struct m_can_classdev *mcan_class = &priv->cdev; m_can_class_unregister(mcan_class); - + pm_runtime_disable(mcan_class->dev); m_can_class_free_dev(mcan_class->net); } -- cgit v1.2.3 From 3d9db29b45f970d81acf61cf91a65442efbeb997 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Wed, 6 Aug 2025 16:56:15 +0200 Subject: can: m_can: m_can_handle_state_errors(): fix CAN state transition to Error Active 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 change") Reviewed-by: Markus Schneider-Pargmann Link: https://patch.msgid.link/20250929-m_can-fix-state-handling-v4-2-682b49b49d9a@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/m_can/m_can.c | 53 ++++++++++++++++++++++++++----------------- 1 file changed, 32 insertions(+), 21 deletions(-) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index e1d725979685..ac864183a536 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 = 0; switch (new_state) { + case CAN_STATE_ERROR_ACTIVE: + cdev->can.state = 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); switch (new_state) { + case CAN_STATE_ERROR_ACTIVE: + cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT; + cf->data[1] = CAN_ERR_CRTL_ACTIVE; + cf->data[6] = bec.txerr; + cf->data[7] = bec.rxerr; + break; case CAN_STATE_ERROR_WARNING: /* error warning state */ cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT; @@ -877,30 +886,33 @@ static int m_can_handle_state_change(struct net_device *dev, return 1; } -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) { - struct m_can_classdev *cdev = netdev_priv(dev); - int work_done = 0; + u32 reg_psr; - if (psr & PSR_EW && cdev->can.state != CAN_STATE_ERROR_WARNING) { - netdev_dbg(dev, "entered error warning state\n"); - work_done += m_can_handle_state_change(dev, - CAN_STATE_ERROR_WARNING); - } + reg_psr = m_can_read(cdev, M_CAN_PSR); - if (psr & PSR_EP && cdev->can.state != CAN_STATE_ERROR_PASSIVE) { - netdev_dbg(dev, "entered error passive state\n"); - work_done += m_can_handle_state_change(dev, - CAN_STATE_ERROR_PASSIVE); - } + 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; - if (psr & PSR_BO && cdev->can.state != CAN_STATE_BUS_OFF) { - netdev_dbg(dev, "entered error bus off state\n"); - work_done += m_can_handle_state_change(dev, - CAN_STATE_BUS_OFF); - } + return CAN_STATE_ERROR_ACTIVE; +} - return work_done; +static int m_can_handle_state_errors(struct net_device *dev) +{ + struct m_can_classdev *cdev = netdev_priv(dev); + enum can_state new_state; + + new_state = m_can_state_get_by_psr(cdev); + if (new_state == cdev->can.state) + return 0; + + return m_can_handle_state_change(dev, new_state); } 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, int quota, u32 irqstatus) } if (irqstatus & IR_ERR_STATE) - work_done += m_can_handle_state_errors(dev, - m_can_read(cdev, M_CAN_PSR)); + work_done += m_can_handle_state_errors(dev); if (irqstatus & IR_ERR_BUS_30X) work_done += m_can_handle_bus_errors(dev, irqstatus, -- cgit v1.2.3 From 4942c42fe1849e6d68dfb5b36ccba344a9fac016 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Wed, 6 Aug 2025 18:24:12 +0200 Subject: can: m_can: m_can_chip_config(): bring up interface in correct state In some SoCs (observed on the STM32MP15) the M_CAN IP core keeps the CAN state and CAN error counters over an internal reset cycle. An external reset is not always possible, due to the shared reset with the other CAN core. This caused the core not always be in Error Active state when bringing up the controller. Instead of always setting the CAN state to Error Active in m_can_chip_config(), fix this by reading and decoding the Protocol Status Regitser (PSR) and set the CAN state accordingly. Fixes: e0d1f4816f2a ("can: m_can: add Bosch M_CAN controller support") Reviewed-by: Markus Schneider-Pargmann Link: https://patch.msgid.link/20250929-m_can-fix-state-handling-v4-3-682b49b49d9a@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/m_can/m_can.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index ac864183a536..b6db5b57241c 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -1617,7 +1617,7 @@ static int m_can_start(struct net_device *dev) netdev_queue_set_dql_min_limit(netdev_get_tx_queue(cdev->net, 0), cdev->tx_max_coalesced_frames); - cdev->can.state = CAN_STATE_ERROR_ACTIVE; + cdev->can.state = m_can_state_get_by_psr(cdev); m_can_enable_all_interrupts(cdev); -- cgit v1.2.3 From a9e30a22d6f23a2684c248871cad4c3061181639 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Tue, 12 Aug 2025 16:58:31 +0200 Subject: can: m_can: fix CAN state in system PM A suspend/resume cycle on a down interface results in the interface coming up in Error Active state. A suspend/resume cycle on an Up interface will always result in Error Active state, regardless of the actual CAN state. During suspend, only set running interfaces to CAN_STATE_SLEEPING. During resume only touch the CAN state of running interfaces. For wakeup sources, set the CAN state depending on the Protocol Status Regitser (PSR), for non wakeup source interfaces m_can_start() will do the same. Fixes: e0d1f4816f2a ("can: m_can: add Bosch M_CAN controller support") Reviewed-by: Markus Schneider-Pargmann Link: https://patch.msgid.link/20250929-m_can-fix-state-handling-v4-4-682b49b49d9a@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/m_can/m_can.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index b6db5b57241c..f2576e577058 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -2503,12 +2503,11 @@ int m_can_class_suspend(struct device *dev) } m_can_clk_stop(cdev); + cdev->can.state = CAN_STATE_SLEEPING; } pinctrl_pm_select_sleep_state(dev); - cdev->can.state = CAN_STATE_SLEEPING; - return ret; } EXPORT_SYMBOL_GPL(m_can_class_suspend); @@ -2521,8 +2520,6 @@ int m_can_class_resume(struct device *dev) pinctrl_pm_select_default_state(dev); - cdev->can.state = CAN_STATE_ERROR_ACTIVE; - if (netif_running(ndev)) { ret = m_can_clk_start(cdev); if (ret) @@ -2540,6 +2537,8 @@ int m_can_class_resume(struct device *dev) if (cdev->ops->init) ret = cdev->ops->init(cdev); + cdev->can.state = m_can_state_get_by_psr(cdev); + m_can_write(cdev, M_CAN_IE, cdev->active_interrupts); } else { ret = m_can_start(ndev); -- cgit v1.2.3