1 files changed, 257 insertions, 145 deletions

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 14b231c4d7ec..6c656bfdb323 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -379,38 +379,72 @@ m_can_txe_fifo_read(struct m_can_classdev *cdev, u32 fgi, u32 offset, u32 *val)
 	return cdev->ops->read_fifo(cdev, addr_offset, val, 1);
 }
 
-static void m_can_config_endisable(struct m_can_classdev *cdev, bool enable)
-{
-	u32 cccr = m_can_read(cdev, M_CAN_CCCR);
-	u32 timeout = 10;
-	u32 val = 0;
-
-	/* Clear the Clock stop request if it was set */
-	if (cccr & CCCR_CSR)
-		cccr &= ~CCCR_CSR;
-
-	if (enable) {
-		/* enable m_can configuration */
-		m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT);
-		udelay(5);
-		/* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */
-		m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE);
-	} else {
-		m_can_write(cdev, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE));
+static int m_can_cccr_update_bits(struct m_can_classdev *cdev, u32 mask, u32 val)
+{
+	u32 val_before = m_can_read(cdev, M_CAN_CCCR);
+	u32 val_after = (val_before & ~mask) | val;
+	size_t tries = 10;
+
+	if (!(mask & CCCR_INIT) && !(val_before & CCCR_INIT)) {
+		dev_err(cdev->dev,
+			"refusing to configure device when in normal mode\n");
+		return -EBUSY;
 	}
 
-	/* there's a delay for module initialization */
-	if (enable)
-		val = CCCR_INIT | CCCR_CCE;
+	/* The chip should be in standby mode when changing the CCCR register,
+	 * and some chips set the CSR and CSA bits when in standby. Furthermore,
+	 * the CSR and CSA bits should be written as zeros, even when they read
+	 * ones.
+	 */
+	val_after &= ~(CCCR_CSR | CCCR_CSA);
+
+	while (tries--) {
+		u32 val_read;
 
-	while ((m_can_read(cdev, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) {
-		if (timeout == 0) {
-			netdev_warn(cdev->net, "Failed to init module\n");
-			return;
-		}
-		timeout--;
-		udelay(1);
+		/* Write the desired value in each try, as setting some bits in
+		 * the CCCR register require other bits to be set first. E.g.
+		 * setting the NISO bit requires setting the CCE bit first.
+		 */
+		m_can_write(cdev, M_CAN_CCCR, val_after);
+
+		val_read = m_can_read(cdev, M_CAN_CCCR) & ~(CCCR_CSR | CCCR_CSA);
+
+		if (val_read == val_after)
+			return 0;
+
+		usleep_range(1, 5);
 	}
+
+	return -ETIMEDOUT;
+}
+
+static int m_can_config_enable(struct m_can_classdev *cdev)
+{
+	int err;
+
+	/* CCCR_INIT must be set in order to set CCCR_CCE, but access to
+	 * configuration registers should only be enabled when in standby mode,
+	 * where CCCR_INIT is always set.
+	 */
+	err = m_can_cccr_update_bits(cdev, CCCR_CCE, CCCR_CCE);
+	if (err)
+		netdev_err(cdev->net, "failed to enable configuration mode\n");
+
+	return err;
+}
+
+static int m_can_config_disable(struct m_can_classdev *cdev)
+{
+	int err;
+
+	/* Only clear CCCR_CCE, since CCCR_INIT cannot be cleared while in
+	 * standby mode
+	 */
+	err = m_can_cccr_update_bits(cdev, CCCR_CCE, 0);
+	if (err)
+		netdev_err(cdev->net, "failed to disable configuration registers\n");
+
+	return err;
 }
 
 static void m_can_interrupt_enable(struct m_can_classdev *cdev, u32 interrupts)
@@ -449,11 +483,10 @@ static inline void m_can_disable_all_interrupts(struct m_can_classdev *cdev)
 {
 	m_can_coalescing_disable(cdev);
 	m_can_write(cdev, M_CAN_ILE, 0x0);
-	cdev->active_interrupts = 0x0;
 
 	if (!cdev->net->irq) {
 		dev_dbg(cdev->dev, "Stop hrtimer\n");
-		hrtimer_cancel(&cdev->hrtimer);
+		hrtimer_try_to_cancel(&cdev->hrtimer);
 	}
 }
 
@@ -662,47 +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);
 
@@ -1003,22 +1049,6 @@ end:
 	return work_done;
 }
 
-static int m_can_rx_peripheral(struct net_device *dev, u32 irqstatus)
-{
-	struct m_can_classdev *cdev = netdev_priv(dev);
-	int work_done;
-
-	work_done = m_can_rx_handler(dev, NAPI_POLL_WEIGHT, irqstatus);
-
-	/* Don't re-enable interrupts if the driver had a fatal error
-	 * (e.g., FIFO read failure).
-	 */
-	if (work_done < 0)
-		m_can_disable_all_interrupts(cdev);
-
-	return work_done;
-}
-
 static int m_can_poll(struct napi_struct *napi, int quota)
 {
 	struct net_device *dev = napi->dev;
@@ -1183,25 +1213,39 @@ static void m_can_coalescing_update(struct m_can_classdev *cdev, u32 ir)
 			      HRTIMER_MODE_REL);
 }
 
-static irqreturn_t m_can_isr(int irq, void *dev_id)
+/* This interrupt handler is called either from the interrupt thread or a
+ * hrtimer. This has implications like cancelling a timer won't be possible
+ * blocking.
+ */
+static int m_can_interrupt_handler(struct m_can_classdev *cdev)
 {
-	struct net_device *dev = (struct net_device *)dev_id;
-	struct m_can_classdev *cdev = netdev_priv(dev);
-	u32 ir;
+	struct net_device *dev = cdev->net;
+	u32 ir = 0, ir_read;
+	int ret;
 
-	if (pm_runtime_suspended(cdev->dev)) {
-		m_can_coalescing_disable(cdev);
+	if (pm_runtime_suspended(cdev->dev))
 		return IRQ_NONE;
+
+	/* 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;
 	}
 
-	ir = m_can_read(cdev, M_CAN_IR);
 	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);
 
@@ -1216,11 +1260,9 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
 			m_can_disable_all_interrupts(cdev);
 			napi_schedule(&cdev->napi);
 		} else {
-			int pkts;
-
-			pkts = m_can_rx_peripheral(dev, ir);
-			if (pkts < 0)
-				goto out_fail;
+			ret = m_can_rx_handler(dev, NAPI_POLL_WEIGHT, ir);
+			if (ret < 0)
+				return ret;
 		}
 	}
 
@@ -1238,8 +1280,9 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
 	} else  {
 		if (ir & (IR_TEFN | IR_TEFW)) {
 			/* New TX FIFO Element arrived */
-			if (m_can_echo_tx_event(dev) != 0)
-				goto out_fail;
+			ret = m_can_echo_tx_event(dev);
+			if (ret != 0)
+				return ret;
 		}
 	}
 
@@ -1247,16 +1290,31 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
 		can_rx_offload_threaded_irq_finish(&cdev->offload);
 
 	return IRQ_HANDLED;
+}
 
-out_fail:
-	m_can_disable_all_interrupts(cdev);
-	return IRQ_HANDLED;
+static irqreturn_t m_can_isr(int irq, void *dev_id)
+{
+	struct net_device *dev = (struct net_device *)dev_id;
+	struct m_can_classdev *cdev = netdev_priv(dev);
+	int ret;
+
+	ret =  m_can_interrupt_handler(cdev);
+	if (ret < 0) {
+		m_can_disable_all_interrupts(cdev);
+		return IRQ_HANDLED;
+	}
+
+	return ret;
 }
 
 static enum hrtimer_restart m_can_coalescing_timer(struct hrtimer *timer)
 {
 	struct m_can_classdev *cdev = container_of(timer, struct m_can_classdev, hrtimer);
 
+	if (cdev->can.state == CAN_STATE_BUS_OFF ||
+	    cdev->can.state == CAN_STATE_STOPPED)
+		return HRTIMER_NORESTART;
+
 	irq_wake_thread(cdev->net->irq, cdev->net);
 
 	return HRTIMER_NORESTART;
@@ -1314,7 +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;
 
@@ -1401,9 +1459,12 @@ static int m_can_chip_config(struct net_device *dev)
 
 	/* Disable unused interrupts */
 	interrupts &= ~(IR_ARA | IR_ELO | IR_DRX | IR_TEFF | IR_TFE | IR_TCF |
-			IR_HPM | IR_RF1F | IR_RF1W | IR_RF1N | IR_RF0F);
+			IR_HPM | IR_RF1F | IR_RF1W | IR_RF1N | IR_RF0F |
+			IR_TSW);
 
-	m_can_config_endisable(cdev, true);
+	err = m_can_config_enable(cdev);
+	if (err)
+		return err;
 
 	/* RX Buffer/FIFO Element Size 64 bytes data field */
 	m_can_write(cdev, M_CAN_RXESC,
@@ -1506,6 +1567,7 @@ static int m_can_chip_config(struct net_device *dev)
 		else
 			interrupts &= ~(IR_ERR_LEC_31X);
 	}
+	cdev->active_interrupts = 0;
 	m_can_interrupt_enable(cdev, interrupts);
 
 	/* route all interrupts to INT0 */
@@ -1521,7 +1583,9 @@ static int m_can_chip_config(struct net_device *dev)
 		    FIELD_PREP(TSCC_TCP_MASK, 0xf) |
 		    FIELD_PREP(TSCC_TSS_MASK, TSCC_TSS_INTERNAL));
 
-	m_can_config_endisable(cdev, false);
+	err = m_can_config_disable(cdev);
+	if (err)
+		return err;
 
 	if (cdev->ops->init)
 		cdev->ops->init(cdev);
@@ -1550,7 +1614,11 @@ static int m_can_start(struct net_device *dev)
 		cdev->tx_fifo_putidx = FIELD_GET(TXFQS_TFQPI_MASK,
 						 m_can_read(cdev, M_CAN_TXFQS));
 
-	return 0;
+	ret = m_can_cccr_update_bits(cdev, CCCR_INIT, 0);
+	if (ret)
+		netdev_err(dev, "failed to enter normal mode\n");
+
+	return ret;
 }
 
 static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
@@ -1599,43 +1667,37 @@ static int m_can_check_core_release(struct m_can_classdev *cdev)
 }
 
 /* Selectable Non ISO support only in version 3.2.x
- * This function checks if the bit is writable.
+ * Return 1 if the bit is writable, 0 if it is not, or negative on error.
  */
-static bool m_can_niso_supported(struct m_can_classdev *cdev)
+static int m_can_niso_supported(struct m_can_classdev *cdev)
 {
-	u32 cccr_reg, cccr_poll = 0;
-	int niso_timeout = -ETIMEDOUT;
-	int i;
+	int ret, niso;
 
-	m_can_config_endisable(cdev, true);
-	cccr_reg = m_can_read(cdev, M_CAN_CCCR);
-	cccr_reg |= CCCR_NISO;
-	m_can_write(cdev, M_CAN_CCCR, cccr_reg);
+	ret = m_can_config_enable(cdev);
+	if (ret)
+		return ret;
 
-	for (i = 0; i <= 10; i++) {
-		cccr_poll = m_can_read(cdev, M_CAN_CCCR);
-		if (cccr_poll == cccr_reg) {
-			niso_timeout = 0;
-			break;
-		}
+	/* First try to set the NISO bit. */
+	niso = m_can_cccr_update_bits(cdev, CCCR_NISO, CCCR_NISO);
 
-		usleep_range(1, 5);
+	/* Then clear the it again. */
+	ret = m_can_cccr_update_bits(cdev, CCCR_NISO, 0);
+	if (ret) {
+		dev_err(cdev->dev, "failed to revert the NON-ISO bit in CCCR\n");
+		return ret;
 	}
 
-	/* Clear NISO */
-	cccr_reg &= ~(CCCR_NISO);
-	m_can_write(cdev, M_CAN_CCCR, cccr_reg);
-
-	m_can_config_endisable(cdev, false);
+	ret = m_can_config_disable(cdev);
+	if (ret)
+		return ret;
 
-	/* return false if time out (-ETIMEDOUT), else return true */
-	return !niso_timeout;
+	return niso == 0;
 }
 
 static int m_can_dev_setup(struct m_can_classdev *cdev)
 {
 	struct net_device *dev = cdev->net;
-	int m_can_version, err;
+	int m_can_version, err, niso;
 
 	m_can_version = m_can_check_core_release(cdev);
 	/* return if unsupported version */
@@ -1645,6 +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);
 
@@ -1668,7 +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 */
@@ -1676,17 +1746,19 @@ 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;
 
-		cdev->can.ctrlmode_supported |=
-			(m_can_niso_supported(cdev) ?
-			 CAN_CTRLMODE_FD_NON_ISO : 0);
+		niso = m_can_niso_supported(cdev);
+		if (niso < 0)
+			return niso;
+		if (niso)
+			cdev->can.ctrlmode_supported |= CAN_CTRLMODE_FD_NON_ISO;
 		break;
 	default:
 		dev_err(cdev->dev, "Unsupported version number: %2d",
@@ -1694,24 +1766,32 @@ static int m_can_dev_setup(struct m_can_classdev *cdev)
 		return -EINVAL;
 	}
 
-	if (cdev->ops->init)
-		cdev->ops->init(cdev);
-
 	return 0;
 }
 
 static void m_can_stop(struct net_device *dev)
 {
 	struct m_can_classdev *cdev = netdev_priv(dev);
+	int ret;
 
 	/* disable all interrupts */
 	m_can_disable_all_interrupts(cdev);
 
 	/* Set init mode to disengage from the network */
-	m_can_config_endisable(cdev, true);
+	ret = m_can_cccr_update_bits(cdev, CCCR_INIT, CCCR_INIT);
+	if (ret)
+		netdev_err(dev, "failed to enter standby mode: %pe\n",
+			   ERR_PTR(ret));
 
 	/* 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)
@@ -1720,12 +1800,9 @@ static int m_can_close(struct net_device *dev)
 
 	netif_stop_queue(dev);
 
-	if (!cdev->is_peripheral)
-		napi_disable(&cdev->napi);
-
 	m_can_stop(dev);
-	m_can_clk_stop(cdev);
-	free_irq(dev->irq, dev);
+	if (dev->irq)
+		free_irq(dev->irq, dev);
 
 	m_can_clean(dev);
 
@@ -1733,10 +1810,13 @@ static int m_can_close(struct net_device *dev)
 		destroy_workqueue(cdev->tx_wq);
 		cdev->tx_wq = NULL;
 		can_rx_offload_disable(&cdev->offload);
+	} else {
+		napi_disable(&cdev->napi);
 	}
 
 	close_candev(dev);
 
+	m_can_clk_stop(cdev);
 	phy_power_off(cdev->transceiver);
 
 	return 0;
@@ -1948,8 +2028,17 @@ static enum hrtimer_restart hrtimer_callback(struct hrtimer *timer)
 {
 	struct m_can_classdev *cdev = container_of(timer, struct
 						   m_can_classdev, hrtimer);
+	int ret;
+
+	if (cdev->can.state == CAN_STATE_BUS_OFF ||
+	    cdev->can.state == CAN_STATE_STOPPED)
+		return HRTIMER_NORESTART;
+
+	ret = m_can_interrupt_handler(cdev);
 
-	m_can_isr(0, cdev->net);
+	/* On error or if napi is scheduled to read, stop the timer */
+	if (ret < 0 || napi_is_scheduled(&cdev->napi))
+		return HRTIMER_NORESTART;
 
 	hrtimer_forward_now(timer, ms_to_ktime(HRTIMER_POLL_INTERVAL_MS));
 
@@ -1978,6 +2067,8 @@ static int m_can_open(struct net_device *dev)
 
 	if (cdev->is_peripheral)
 		can_rx_offload_enable(&cdev->offload);
+	else
+		napi_enable(&cdev->napi);
 
 	/* register interrupt handler */
 	if (cdev->is_peripheral) {
@@ -2009,21 +2100,23 @@ static int m_can_open(struct net_device *dev)
 	/* start the m_can controller */
 	err = m_can_start(dev);
 	if (err)
-		goto exit_irq_fail;
-
-	if (!cdev->is_peripheral)
-		napi_enable(&cdev->napi);
+		goto exit_start_fail;
 
 	netif_start_queue(dev);
 
 	return 0;
 
+exit_start_fail:
+	if (cdev->is_peripheral || dev->irq)
+		free_irq(dev->irq, dev);
 exit_irq_fail:
 	if (cdev->is_peripheral)
 		destroy_workqueue(cdev->tx_wq);
 out_wq_fail:
 	if (cdev->is_peripheral)
 		can_rx_offload_disable(&cdev->offload);
+	else
+		napi_disable(&cdev->napi);
 	close_candev(dev);
 exit_disable_clks:
 	m_can_clk_stop(cdev);
@@ -2129,7 +2222,7 @@ static int m_can_set_coalesce(struct net_device *dev,
 	return 0;
 }
 
-static const struct ethtool_ops m_can_ethtool_ops = {
+static const struct ethtool_ops m_can_ethtool_ops_coalescing = {
 	.supported_coalesce_params = ETHTOOL_COALESCE_RX_USECS_IRQ |
 		ETHTOOL_COALESCE_RX_MAX_FRAMES_IRQ |
 		ETHTOOL_COALESCE_TX_USECS_IRQ |
@@ -2140,18 +2233,20 @@ static const struct ethtool_ops m_can_ethtool_ops = {
 	.set_coalesce = m_can_set_coalesce,
 };
 
-static const struct ethtool_ops m_can_ethtool_ops_polling = {
+static const struct ethtool_ops m_can_ethtool_ops = {
 	.get_ts_info = ethtool_op_get_ts_info,
 };
 
-static int register_m_can_dev(struct net_device *dev)
+static int register_m_can_dev(struct m_can_classdev *cdev)
 {
+	struct net_device *dev = cdev->net;
+
 	dev->flags |= IFF_ECHO;	/* we support local echo */
 	dev->netdev_ops = &m_can_netdev_ops;
-	if (dev->irq)
-		dev->ethtool_ops = &m_can_ethtool_ops;
+	if (dev->irq && cdev->is_peripheral)
+		dev->ethtool_ops = &m_can_ethtool_ops_coalescing;
 	else
-		dev->ethtool_ops = &m_can_ethtool_ops_polling;
+		dev->ethtool_ops = &m_can_ethtool_ops;
 
 	return register_candev(dev);
 }
@@ -2284,6 +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;
 }
@@ -2325,19 +2421,18 @@ 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);
 	if (ret)
 		goto rx_offload_del;
 
-	ret = register_m_can_dev(cdev->net);
+	ret = register_m_can_dev(cdev);
 	if (ret) {
 		dev_err(cdev->dev, "registering %s failed (err=%d)\n",
 			cdev->net->name, ret);
@@ -2368,9 +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);
 
@@ -2378,18 +2473,25 @@ 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);
 		netif_device_detach(ndev);
 
 		/* leave the chip running with rx interrupt enabled if it is
-		 * used as a wake-up source.
+		 * used as a wake-up source. Coalescing needs to be reset then,
+		 * the timer is cancelled here, interrupts are done in resume.
 		 */
-		if (cdev->pm_wake_source)
+		if (cdev->pm_wake_source) {
+			hrtimer_cancel(&cdev->hrtimer);
 			m_can_write(cdev, M_CAN_IE, IR_RF0N);
-		else
+
+			if (cdev->ops->deinit)
+				ret = cdev->ops->deinit(cdev);
+		} else {
 			m_can_stop(ndev);
+		}
 
 		m_can_clk_stop(cdev);
 	}
@@ -2398,7 +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);
 
@@ -2406,19 +2508,29 @@ 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;
 
 		if (cdev->pm_wake_source) {
+			/* Restore active interrupts but disable coalescing as
+			 * we may have missed important waterlevel interrupts
+			 * between suspend and resume. Timers are already
+			 * stopped in suspend. Here we enable all interrupts
+			 * 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);
@@ -2432,7 +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);