1 files changed, 77 insertions, 34 deletions

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 16e9e7d7527d..6c656bfdb323 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -695,47 +695,60 @@ static int m_can_handle_lec_err(struct net_device *dev,
 	u32 timestamp = 0;
 
 	cdev->can.can_stats.bus_error++;
-	stats->rx_errors++;
 
 	/* propagate the error condition to the CAN stack */
 	skb = alloc_can_err_skb(dev, &cf);
-	if (unlikely(!skb))
-		return 0;
 
 	/* check for 'last error code' which tells us the
 	 * type of the last error to occur on the CAN bus
 	 */
-	cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+	if (likely(skb))
+		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 
 	switch (lec_type) {
 	case LEC_STUFF_ERROR:
 		netdev_dbg(dev, "stuff error\n");
-		cf->data[2] |= CAN_ERR_PROT_STUFF;
+		stats->rx_errors++;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_STUFF;
 		break;
 	case LEC_FORM_ERROR:
 		netdev_dbg(dev, "form error\n");
-		cf->data[2] |= CAN_ERR_PROT_FORM;
+		stats->rx_errors++;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_FORM;
 		break;
 	case LEC_ACK_ERROR:
 		netdev_dbg(dev, "ack error\n");
-		cf->data[3] = CAN_ERR_PROT_LOC_ACK;
+		stats->tx_errors++;
+		if (likely(skb))
+			cf->data[3] = CAN_ERR_PROT_LOC_ACK;
 		break;
 	case LEC_BIT1_ERROR:
 		netdev_dbg(dev, "bit1 error\n");
-		cf->data[2] |= CAN_ERR_PROT_BIT1;
+		stats->tx_errors++;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_BIT1;
 		break;
 	case LEC_BIT0_ERROR:
 		netdev_dbg(dev, "bit0 error\n");
-		cf->data[2] |= CAN_ERR_PROT_BIT0;
+		stats->tx_errors++;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_BIT0;
 		break;
 	case LEC_CRC_ERROR:
 		netdev_dbg(dev, "CRC error\n");
-		cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
+		stats->rx_errors++;
+		if (likely(skb))
+			cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
 		break;
 	default:
 		break;
 	}
 
+	if (unlikely(!skb))
+		return 0;
+
 	if (cdev->is_peripheral)
 		timestamp = m_can_get_timestamp(cdev);
 
@@ -1207,20 +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);
 
@@ -1347,7 +1372,7 @@ static int m_can_set_bittiming(struct net_device *dev)
 {
 	struct m_can_classdev *cdev = netdev_priv(dev);
 	const struct can_bittiming *bt = &cdev->can.bittiming;
-	const struct can_bittiming *dbt = &cdev->can.data_bittiming;
+	const struct can_bittiming *dbt = &cdev->can.fd.data_bittiming;
 	u16 brp, sjw, tseg1, tseg2;
 	u32 reg_btp;
 
@@ -1682,6 +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);
 
@@ -1705,7 +1738,7 @@ static int m_can_dev_setup(struct m_can_classdev *cdev)
 		if (err)
 			return err;
 		cdev->can.bittiming_const = &m_can_bittiming_const_30X;
-		cdev->can.data_bittiming_const = &m_can_data_bittiming_const_30X;
+		cdev->can.fd.data_bittiming_const = &m_can_data_bittiming_const_30X;
 		break;
 	case 31:
 		/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */
@@ -1713,13 +1746,13 @@ static int m_can_dev_setup(struct m_can_classdev *cdev)
 		if (err)
 			return err;
 		cdev->can.bittiming_const = &m_can_bittiming_const_31X;
-		cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X;
+		cdev->can.fd.data_bittiming_const = &m_can_data_bittiming_const_31X;
 		break;
 	case 32:
 	case 33:
 		/* Support both MCAN version v3.2.x and v3.3.0 */
 		cdev->can.bittiming_const = &m_can_bittiming_const_31X;
-		cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X;
+		cdev->can.fd.data_bittiming_const = &m_can_data_bittiming_const_31X;
 
 		niso = m_can_niso_supported(cdev);
 		if (niso < 0)
@@ -1733,11 +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)
@@ -1756,6 +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)
@@ -2343,6 +2379,7 @@ struct m_can_classdev *m_can_class_allocate_dev(struct device *dev,
 	SET_NETDEV_DEV(net_dev, dev);
 
 	m_can_of_parse_mram(class_dev, mram_config_vals);
+	spin_lock_init(&class_dev->tx_handling_spinlock);
 out:
 	return class_dev;
 }
@@ -2384,12 +2421,11 @@ int m_can_class_register(struct m_can_classdev *cdev)
 
 	if (!cdev->net->irq) {
 		dev_dbg(cdev->dev, "Polling enabled, initialize hrtimer");
-		hrtimer_init(&cdev->hrtimer, CLOCK_MONOTONIC,
-			     HRTIMER_MODE_REL_PINNED);
-		cdev->hrtimer.function = &hrtimer_callback;
+		hrtimer_setup(&cdev->hrtimer, &hrtimer_callback, CLOCK_MONOTONIC,
+			      HRTIMER_MODE_REL_PINNED);
 	} else {
-		hrtimer_init(&cdev->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-		cdev->hrtimer.function = m_can_coalescing_timer;
+		hrtimer_setup(&cdev->hrtimer, m_can_coalescing_timer, CLOCK_MONOTONIC,
+			      HRTIMER_MODE_REL);
 	}
 
 	ret = m_can_dev_setup(cdev);
@@ -2427,9 +2463,9 @@ EXPORT_SYMBOL_GPL(m_can_class_register);
 
 void m_can_class_unregister(struct m_can_classdev *cdev)
 {
+	unregister_candev(cdev->net);
 	if (cdev->is_peripheral)
 		can_rx_offload_del(&cdev->offload);
-	unregister_candev(cdev->net);
 }
 EXPORT_SYMBOL_GPL(m_can_class_unregister);
 
@@ -2437,6 +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);
@@ -2449,6 +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);
 		}
@@ -2460,7 +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);
 
@@ -2468,14 +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;
@@ -2488,6 +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);
@@ -2501,7 +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);