1 files changed, 44 insertions, 14 deletions

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 533bcb77c9f9..d025d4163fd1 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -1220,20 +1220,32 @@ static void m_can_coalescing_update(struct m_can_classdev *cdev, u32 ir)
 static int m_can_interrupt_handler(struct m_can_classdev *cdev)
 {
 	struct net_device *dev = cdev->net;
-	u32 ir;
+	u32 ir = 0, ir_read;
 	int ret;
 
 	if (pm_runtime_suspended(cdev->dev))
 		return IRQ_NONE;
 
-	ir = m_can_read(cdev, M_CAN_IR);
+	/* The m_can controller signals its interrupt status as a level, but
+	 * depending in the integration the CPU may interpret the signal as
+	 * edge-triggered (for example with m_can_pci). For these
+	 * edge-triggered integrations, we must observe that IR is 0 at least
+	 * once to be sure that the next interrupt will generate an edge.
+	 */
+	while ((ir_read = m_can_read(cdev, M_CAN_IR)) != 0) {
+		ir |= ir_read;
+
+		/* ACK all irqs */
+		m_can_write(cdev, M_CAN_IR, ir);
+
+		if (!cdev->irq_edge_triggered)
+			break;
+	}
+
 	m_can_coalescing_update(cdev, ir);
 	if (!ir)
 		return IRQ_NONE;
 
-	/* ACK all irqs */
-	m_can_write(cdev, M_CAN_IR, ir);
-
 	if (cdev->ops->clear_interrupts)
 		cdev->ops->clear_interrupts(cdev);
 
@@ -1695,6 +1707,14 @@ static int m_can_dev_setup(struct m_can_classdev *cdev)
 		return -EINVAL;
 	}
 
+	/* Write the INIT bit, in case no hardware reset has happened before
+	 * the probe (for example, it was observed that the Intel Elkhart Lake
+	 * SoCs do not properly reset the CAN controllers on reboot)
+	 */
+	err = m_can_cccr_update_bits(cdev, CCCR_INIT, CCCR_INIT);
+	if (err)
+		return err;
+
 	if (!cdev->is_peripheral)
 		netif_napi_add(dev, &cdev->napi, m_can_poll);
 
@@ -1746,11 +1766,7 @@ static int m_can_dev_setup(struct m_can_classdev *cdev)
 		return -EINVAL;
 	}
 
-	/* Forcing standby mode should be redundant, as the chip should be in
-	 * standby after a reset. Write the INIT bit anyways, should the chip
-	 * be configured by previous stage.
-	 */
-	return m_can_cccr_update_bits(cdev, CCCR_INIT, CCCR_INIT);
+	return 0;
 }
 
 static void m_can_stop(struct net_device *dev)
@@ -1769,6 +1785,13 @@ static void m_can_stop(struct net_device *dev)
 
 	/* set the state as STOPPED */
 	cdev->can.state = CAN_STATE_STOPPED;
+
+	if (cdev->ops->deinit) {
+		ret = cdev->ops->deinit(cdev);
+		if (ret)
+			netdev_err(dev, "failed to deinitialize: %pe\n",
+				   ERR_PTR(ret));
+	}
 }
 
 static int m_can_close(struct net_device *dev)
@@ -2450,6 +2473,7 @@ int m_can_class_suspend(struct device *dev)
 {
 	struct m_can_classdev *cdev = dev_get_drvdata(dev);
 	struct net_device *ndev = cdev->net;
+	int ret = 0;
 
 	if (netif_running(ndev)) {
 		netif_stop_queue(ndev);
@@ -2462,6 +2486,9 @@ int m_can_class_suspend(struct device *dev)
 		if (cdev->pm_wake_source) {
 			hrtimer_cancel(&cdev->hrtimer);
 			m_can_write(cdev, M_CAN_IE, IR_RF0N);
+
+			if (cdev->ops->deinit)
+				ret = cdev->ops->deinit(cdev);
 		} else {
 			m_can_stop(ndev);
 		}
@@ -2473,7 +2500,7 @@ int m_can_class_suspend(struct device *dev)
 
 	cdev->can.state = CAN_STATE_SLEEPING;
 
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(m_can_class_suspend);
 
@@ -2481,14 +2508,13 @@ int m_can_class_resume(struct device *dev)
 {
 	struct m_can_classdev *cdev = dev_get_drvdata(dev);
 	struct net_device *ndev = cdev->net;
+	int ret = 0;
 
 	pinctrl_pm_select_default_state(dev);
 
 	cdev->can.state = CAN_STATE_ERROR_ACTIVE;
 
 	if (netif_running(ndev)) {
-		int ret;
-
 		ret = m_can_clk_start(cdev);
 		if (ret)
 			return ret;
@@ -2501,6 +2527,10 @@ int m_can_class_resume(struct device *dev)
 			 * again.
 			 */
 			cdev->active_interrupts |= IR_RF0N | IR_TEFN;
+
+			if (cdev->ops->init)
+				ret = cdev->ops->init(cdev);
+
 			m_can_write(cdev, M_CAN_IE, cdev->active_interrupts);
 		} else {
 			ret  = m_can_start(ndev);
@@ -2514,7 +2544,7 @@ int m_can_class_resume(struct device *dev)
 		netif_start_queue(ndev);
 	}
 
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(m_can_class_resume);