Merge tag 'linux-can-next-for-6.11-20240629' of...

Merge tag 'linux-can-next-for-6.11-20240629' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2024-06-29

Geert Uytterhoeven contributes 3 patches with small improvements and
cleanups for the rcar_canfd driver.

A patch by Christophe JAILLET constifies the struct m_can_ops in the
m_can driver to reduce the code size.

The last 9 patches are by me an work around erratum DS80000789E 6 of
mcp2518fd.

* tag 'linux-can-next-for-6.11-20240629' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next:
  can: mcp251xfd: tef: update workaround for erratum DS80000789E 6 of mcp2518fd
  can: mcp251xfd: tef: prepare to workaround broken TEF FIFO tail index erratum
  can: mcp251xfd: rx: add workaround for erratum DS80000789E 6 of mcp2518fd
  can: mcp251xfd: rx: prepare to workaround broken RX FIFO head index erratum
  can: mcp251xfd: mcp251xfd_handle_rxif_ring_uinc(): factor out in separate function
  can: mcp251xfd: clarify the meaning of timestamp
  can: mcp251xfd: move mcp251xfd_timestamp_start()/stop() into mcp251xfd_chip_start/stop()
  can: mcp251xfd: update errata references
  can: mcp251xfd: properly indent labels
  can: gs_usb: add VID/PID for Xylanta SAINT3 product family
  can: m_can: Constify struct m_can_ops
  can: rcar_canfd: Remove superfluous parentheses in address calculations
  can: rcar_canfd: Improve printing of global operational state
  can: rcar_canfd: Simplify clock handling
====================

Link: https://patch.msgid.link/20240629114017.1080160-1-mkl@pengutronix.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/can/m_can/m_can.h

@@ -91,7 +91,7 @@ struct m_can_classdev {
 
 	ktime_t irq_timer_wait;
 
-	struct m_can_ops *ops;
+	const struct m_can_ops *ops;
 
 	int version;
 	u32 irqstatus;

drivers/net/can/m_can/m_can_pci.c

@@ -77,7 +77,7 @@ static int iomap_write_fifo(struct m_can_classdev *cdev, int offset,
 	return 0;
 }
 
-static struct m_can_ops m_can_pci_ops = {
+static const struct m_can_ops m_can_pci_ops = {
 	.read_reg = iomap_read_reg,
 	.write_reg = iomap_write_reg,
 	.write_fifo = iomap_write_fifo,

drivers/net/can/m_can/m_can_platform.c

@@ -68,7 +68,7 @@ static int iomap_write_fifo(struct m_can_classdev *cdev, int offset,
 	return 0;
 }
 
-static struct m_can_ops m_can_plat_ops = {
+static const struct m_can_ops m_can_plat_ops = {
 	.read_reg = iomap_read_reg,
 	.write_reg = iomap_write_reg,
 	.write_fifo = iomap_write_fifo,

drivers/net/can/m_can/tcan4x5x-core.c

@@ -357,7 +357,7 @@ static int tcan4x5x_get_gpios(struct m_can_classdev *cdev,
 	return 0;
 }
 
-static struct m_can_ops tcan4x5x_ops = {
+static const struct m_can_ops tcan4x5x_ops = {
 	.init = tcan4x5x_init,
 	.read_reg = tcan4x5x_read_reg,
 	.write_reg = tcan4x5x_write_reg,

drivers/net/can/rcar/rcar_canfd.c

@@ -508,12 +508,6 @@
  */
 #define RCANFD_CFFIFO_IDX		0
 
-/* fCAN clock select register settings */
-enum rcar_canfd_fcanclk {
-	RCANFD_CANFDCLK = 0,		/* CANFD clock */
-	RCANFD_EXTCLK,			/* Externally input clock */
-};
-
 struct rcar_canfd_global;
 
 struct rcar_canfd_hw_info {
@@ -545,8 +539,8 @@ struct rcar_canfd_global {
 	struct platform_device *pdev;	/* Respective platform device */
 	struct clk *clkp;		/* Peripheral clock */
 	struct clk *can_clk;		/* fCAN clock */
-	enum rcar_canfd_fcanclk fcan;	/* CANFD or Ext clock */
 	unsigned long channels_mask;	/* Enabled channels mask */
+	bool extclk;			/* CANFD or Ext clock */
 	bool fdmode;			/* CAN FD or Classical CAN only mode */
 	struct reset_control *rstc1;
 	struct reset_control *rstc2;
@@ -633,28 +627,28 @@ static inline void rcar_canfd_update(u32 mask, u32 val, u32 __iomem *reg)
 
 static inline u32 rcar_canfd_read(void __iomem *base, u32 offset)
 {
-	return readl(base + (offset));
+	return readl(base + offset);
 }
 
 static inline void rcar_canfd_write(void __iomem *base, u32 offset, u32 val)
 {
-	writel(val, base + (offset));
+	writel(val, base + offset);
 }
 
 static void rcar_canfd_set_bit(void __iomem *base, u32 reg, u32 val)
 {
-	rcar_canfd_update(val, val, base + (reg));
+	rcar_canfd_update(val, val, base + reg);
 }
 
 static void rcar_canfd_clear_bit(void __iomem *base, u32 reg, u32 val)
 {
-	rcar_canfd_update(val, 0, base + (reg));
+	rcar_canfd_update(val, 0, base + reg);
 }
 
 static void rcar_canfd_update_bit(void __iomem *base, u32 reg,
 				  u32 mask, u32 val)
 {
-	rcar_canfd_update(mask, val, base + (reg));
+	rcar_canfd_update(mask, val, base + reg);
 }
 
 static void rcar_canfd_get_data(struct rcar_canfd_channel *priv,
@@ -665,7 +659,7 @@ static void rcar_canfd_get_data(struct rcar_canfd_channel *priv,
 	lwords = DIV_ROUND_UP(cf->len, sizeof(u32));
 	for (i = 0; i < lwords; i++)
 		*((u32 *)cf->data + i) =
-			rcar_canfd_read(priv->base, off + (i * sizeof(u32)));
+			rcar_canfd_read(priv->base, off + i * sizeof(u32));
 }
 
 static void rcar_canfd_put_data(struct rcar_canfd_channel *priv,
@@ -675,7 +669,7 @@ static void rcar_canfd_put_data(struct rcar_canfd_channel *priv,
 
 	lwords = DIV_ROUND_UP(cf->len, sizeof(u32));
 	for (i = 0; i < lwords; i++)
-		rcar_canfd_write(priv->base, off + (i * sizeof(u32)),
+		rcar_canfd_write(priv->base, off + i * sizeof(u32),
 				 *((u32 *)cf->data + i));
 }
 
@@ -777,7 +771,7 @@ static void rcar_canfd_configure_controller(struct rcar_canfd_global *gpriv)
 		cfg |= RCANFD_GCFG_CMPOC;
 
 	/* Set External Clock if selected */
-	if (gpriv->fcan != RCANFD_CANFDCLK)
+	if (gpriv->extclk)
 		cfg |= RCANFD_GCFG_DCS;
 
 	rcar_canfd_set_bit(gpriv->base, RCANFD_GCFG, cfg);
@@ -1941,16 +1935,12 @@ static int rcar_canfd_probe(struct platform_device *pdev)
 			return dev_err_probe(dev, PTR_ERR(gpriv->can_clk),
 					     "cannot get canfd clock\n");
 
-		gpriv->fcan = RCANFD_CANFDCLK;
-
+		/* CANFD clock may be further divided within the IP */
+		fcan_freq = clk_get_rate(gpriv->can_clk) / info->postdiv;
 	} else {
-		gpriv->fcan = RCANFD_EXTCLK;
+		fcan_freq = clk_get_rate(gpriv->can_clk);
+		gpriv->extclk = true;
 	}
-	fcan_freq = clk_get_rate(gpriv->can_clk);
-
-	if (gpriv->fcan == RCANFD_CANFDCLK)
-		/* CANFD clock is further divided by (1/2) within the IP */
-		fcan_freq /= info->postdiv;
 
 	addr = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(addr)) {
@@ -2059,8 +2049,9 @@ static int rcar_canfd_probe(struct platform_device *pdev)
 	}
 
 	platform_set_drvdata(pdev, gpriv);
-	dev_info(dev, "global operational state (clk %d, fdmode %d)\n",
-		 gpriv->fcan, gpriv->fdmode);
+	dev_info(dev, "global operational state (%s clk, %s mode)\n",
+		 gpriv->extclk ? "ext" : "canfd",
+		 gpriv->fdmode ? "fd" : "classical");
 	return 0;
 
 fail_channel:

drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c

@@ -2,7 +2,7 @@
 //
 // mcp251xfd - Microchip MCP251xFD Family CAN controller driver
 //
-// Copyright (c) 2019, 2020, 2021 Pengutronix,
+// Copyright (c) 2019, 2020, 2021, 2023 Pengutronix,
 //               Marc Kleine-Budde <kernel@pengutronix.de>
 //
 // Based on:
@@ -744,6 +744,7 @@ static void mcp251xfd_chip_stop(struct mcp251xfd_priv *priv,
 
 	mcp251xfd_chip_interrupts_disable(priv);
 	mcp251xfd_chip_rx_int_disable(priv);
+	mcp251xfd_timestamp_stop(priv);
 	mcp251xfd_chip_sleep(priv);
 }
 
@@ -763,6 +764,8 @@ static int mcp251xfd_chip_start(struct mcp251xfd_priv *priv)
 	if (err)
 		goto out_chip_stop;
 
+	mcp251xfd_timestamp_start(priv);
+
 	err = mcp251xfd_set_bittiming(priv);
 	if (err)
 		goto out_chip_stop;
@@ -791,7 +794,7 @@ static int mcp251xfd_chip_start(struct mcp251xfd_priv *priv)
 
 	return 0;
 
- out_chip_stop:
+out_chip_stop:
 	mcp251xfd_dump(priv);
 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
 
@@ -867,18 +870,18 @@ static int mcp251xfd_get_berr_counter(const struct net_device *ndev,
 
 static struct sk_buff *
 mcp251xfd_alloc_can_err_skb(struct mcp251xfd_priv *priv,
-			    struct can_frame **cf, u32 *timestamp)
+			    struct can_frame **cf, u32 *ts_raw)
 {
 	struct sk_buff *skb;
 	int err;
 
-	err = mcp251xfd_get_timestamp(priv, timestamp);
+	err = mcp251xfd_get_timestamp_raw(priv, ts_raw);
 	if (err)
 		return NULL;
 
 	skb = alloc_can_err_skb(priv->ndev, cf);
 	if (skb)
-		mcp251xfd_skb_set_timestamp(priv, skb, *timestamp);
+		mcp251xfd_skb_set_timestamp_raw(priv, skb, *ts_raw);
 
 	return skb;
 }
@@ -889,7 +892,7 @@ static int mcp251xfd_handle_rxovif(struct mcp251xfd_priv *priv)
 	struct mcp251xfd_rx_ring *ring;
 	struct sk_buff *skb;
 	struct can_frame *cf;
-	u32 timestamp, rxovif;
+	u32 ts_raw, rxovif;
 	int err, i;
 
 	stats->rx_over_errors++;
@@ -924,14 +927,14 @@ static int mcp251xfd_handle_rxovif(struct mcp251xfd_priv *priv)
 			return err;
 	}
 
-	skb = mcp251xfd_alloc_can_err_skb(priv, &cf, &timestamp);
+	skb = mcp251xfd_alloc_can_err_skb(priv, &cf, &ts_raw);
 	if (!skb)
 		return 0;
 
 	cf->can_id |= CAN_ERR_CRTL;
 	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 
-	err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp);
+	err = can_rx_offload_queue_timestamp(&priv->offload, skb, ts_raw);
 	if (err)
 		stats->rx_fifo_errors++;
 
@@ -948,12 +951,12 @@ static int mcp251xfd_handle_txatif(struct mcp251xfd_priv *priv)
 static int mcp251xfd_handle_ivmif(struct mcp251xfd_priv *priv)
 {
 	struct net_device_stats *stats = &priv->ndev->stats;
-	u32 bdiag1, timestamp;
+	u32 bdiag1, ts_raw;
 	struct sk_buff *skb;
 	struct can_frame *cf = NULL;
 	int err;
 
-	err = mcp251xfd_get_timestamp(priv, &timestamp);
+	err = mcp251xfd_get_timestamp_raw(priv, &ts_raw);
 	if (err)
 		return err;
 
@@ -1035,8 +1038,8 @@ static int mcp251xfd_handle_ivmif(struct mcp251xfd_priv *priv)
 	if (!cf)
 		return 0;
 
-	mcp251xfd_skb_set_timestamp(priv, skb, timestamp);
-	err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp);
+	mcp251xfd_skb_set_timestamp_raw(priv, skb, ts_raw);
+	err = can_rx_offload_queue_timestamp(&priv->offload, skb, ts_raw);
 	if (err)
 		stats->rx_fifo_errors++;
 
@@ -1049,7 +1052,7 @@ static int mcp251xfd_handle_cerrif(struct mcp251xfd_priv *priv)
 	struct sk_buff *skb;
 	struct can_frame *cf = NULL;
 	enum can_state new_state, rx_state, tx_state;
-	u32 trec, timestamp;
+	u32 trec, ts_raw;
 	int err;
 
 	err = regmap_read(priv->map_reg, MCP251XFD_REG_TREC, &trec);
@@ -1079,7 +1082,7 @@ static int mcp251xfd_handle_cerrif(struct mcp251xfd_priv *priv)
 	/* The skb allocation might fail, but can_change_state()
 	 * handles cf == NULL.
 	 */
-	skb = mcp251xfd_alloc_can_err_skb(priv, &cf, &timestamp);
+	skb = mcp251xfd_alloc_can_err_skb(priv, &cf, &ts_raw);
 	can_change_state(priv->ndev, cf, tx_state, rx_state);
 
 	if (new_state == CAN_STATE_BUS_OFF) {
@@ -1110,7 +1113,7 @@ static int mcp251xfd_handle_cerrif(struct mcp251xfd_priv *priv)
 		cf->data[7] = bec.rxerr;
 	}
 
-	err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp);
+	err = can_rx_offload_queue_timestamp(&priv->offload, skb, ts_raw);
 	if (err)
 		stats->rx_fifo_errors++;
 
@@ -1135,7 +1138,7 @@ mcp251xfd_handle_modif(const struct mcp251xfd_priv *priv, bool *set_normal_mode)
 		return 0;
 	}
 
-	/* According to MCP2517FD errata DS80000792B 1., during a TX
+	/* According to MCP2517FD errata DS80000792C 1., during a TX
 	 * MAB underflow, the controller will transition to Restricted
 	 * Operation Mode or Listen Only Mode (depending on SERR2LOM).
 	 *
@@ -1180,7 +1183,7 @@ static int mcp251xfd_handle_serrif(struct mcp251xfd_priv *priv)
 
 	/* TX MAB underflow
 	 *
-	 * According to MCP2517FD Errata DS80000792B 1. a TX MAB
+	 * According to MCP2517FD Errata DS80000792C 1. a TX MAB
 	 * underflow is indicated by SERRIF and MODIF.
 	 *
 	 * In addition to the effects mentioned in the Errata, there
@@ -1224,7 +1227,7 @@ static int mcp251xfd_handle_serrif(struct mcp251xfd_priv *priv)
 
 	/* RX MAB overflow
 	 *
-	 * According to MCP2517FD Errata DS80000792B 1. a RX MAB
+	 * According to MCP2517FD Errata DS80000792C 1. a RX MAB
 	 * overflow is indicated by SERRIF.
 	 *
 	 * In addition to the effects mentioned in the Errata, (most
@@ -1331,7 +1334,8 @@ mcp251xfd_handle_eccif(struct mcp251xfd_priv *priv, bool set_normal_mode)
 		return err;
 
 	/* Errata Reference:
-	 * mcp2517fd: DS80000789B, mcp2518fd: DS80000792C 2.
+	 * mcp2517fd: DS80000789C 3., mcp2518fd: DS80000792E 2.,
+	 * mcp251863: DS80000984A 2.
 	 *
 	 * ECC single error correction does not work in all cases:
 	 *
@@ -1576,7 +1580,7 @@ static irqreturn_t mcp251xfd_irq(int irq, void *dev_id)
 		handled = IRQ_HANDLED;
 	} while (1);
 
- out_fail:
+out_fail:
 	can_rx_offload_threaded_irq_finish(&priv->offload);
 
 	netdev_err(priv->ndev, "IRQ handler returned %d (intf=0x%08x).\n",
@@ -1610,11 +1614,12 @@ static int mcp251xfd_open(struct net_device *ndev)
 	if (err)
 		goto out_mcp251xfd_ring_free;
 
+	mcp251xfd_timestamp_init(priv);
+
 	err = mcp251xfd_chip_start(priv);
 	if (err)
 		goto out_transceiver_disable;
 
-	mcp251xfd_timestamp_init(priv);
 	clear_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
 	can_rx_offload_enable(&priv->offload);
 
@@ -1641,22 +1646,21 @@ static int mcp251xfd_open(struct net_device *ndev)
 
 	return 0;
 
- out_free_irq:
+out_free_irq:
 	free_irq(spi->irq, priv);
- out_destroy_workqueue:
+out_destroy_workqueue:
 	destroy_workqueue(priv->wq);
- out_can_rx_offload_disable:
+out_can_rx_offload_disable:
 	can_rx_offload_disable(&priv->offload);
 	set_bit(MCP251XFD_FLAGS_DOWN, priv->flags);
-	mcp251xfd_timestamp_stop(priv);
- out_transceiver_disable:
+out_transceiver_disable:
 	mcp251xfd_transceiver_disable(priv);
- out_mcp251xfd_ring_free:
+out_mcp251xfd_ring_free:
 	mcp251xfd_ring_free(priv);
- out_pm_runtime_put:
+out_pm_runtime_put:
 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
 	pm_runtime_put(ndev->dev.parent);
- out_close_candev:
+out_close_candev:
 	close_candev(ndev);
 
 	return err;
@@ -1674,7 +1678,6 @@ static int mcp251xfd_stop(struct net_device *ndev)
 	free_irq(ndev->irq, priv);
 	destroy_workqueue(priv->wq);
 	can_rx_offload_disable(&priv->offload);
-	mcp251xfd_timestamp_stop(priv);
 	mcp251xfd_chip_stop(priv, CAN_STATE_STOPPED);
 	mcp251xfd_transceiver_disable(priv);
 	mcp251xfd_ring_free(priv);
@@ -1820,9 +1823,9 @@ mcp251xfd_register_get_dev_id(const struct mcp251xfd_priv *priv, u32 *dev_id,
 	*effective_speed_hz_slow = xfer[0].effective_speed_hz;
 	*effective_speed_hz_fast = xfer[1].effective_speed_hz;
 
- out_kfree_buf_tx:
+out_kfree_buf_tx:
 	kfree(buf_tx);
- out_kfree_buf_rx:
+out_kfree_buf_rx:
 	kfree(buf_rx);
 
 	return err;
@@ -1936,13 +1939,13 @@ static int mcp251xfd_register(struct mcp251xfd_priv *priv)
 
 	return 0;
 
- out_unregister_candev:
+out_unregister_candev:
 	unregister_candev(ndev);
- out_chip_sleep:
+out_chip_sleep:
 	mcp251xfd_chip_sleep(priv);
- out_runtime_disable:
+out_runtime_disable:
 	pm_runtime_disable(ndev->dev.parent);
- out_runtime_put_noidle:
+out_runtime_put_noidle:
 	pm_runtime_put_noidle(ndev->dev.parent);
 	mcp251xfd_clks_and_vdd_disable(priv);
 
@@ -2095,7 +2098,8 @@ static int mcp251xfd_probe(struct spi_device *spi)
 	priv->devtype_data = *(struct mcp251xfd_devtype_data *)spi_get_device_match_data(spi);
 
 	/* Errata Reference:
-	 * mcp2517fd: DS80000792C 5., mcp2518fd: DS80000789C 4.
+	 * mcp2517fd: DS80000792C 5., mcp2518fd: DS80000789E 4.,
+	 * mcp251863: DS80000984A 4.
 	 *
 	 * The SPI can write corrupted data to the RAM at fast SPI
 	 * speeds:
@@ -2155,9 +2159,9 @@ static int mcp251xfd_probe(struct spi_device *spi)
 
 	return 0;
 
- out_can_rx_offload_del:
+out_can_rx_offload_del:
 	can_rx_offload_del(&priv->offload);
- out_free_candev:
+out_free_candev:
 	spi->max_speed_hz = priv->spi_max_speed_hz_orig;
 
 	free_candev(ndev);

drivers/net/can/spi/mcp251xfd/mcp251xfd-dump.c

@@ -94,7 +94,7 @@ static void mcp251xfd_dump_registers(const struct mcp251xfd_priv *priv,
 		kfree(buf);
 	}
 
- out:
+out:
 	mcp251xfd_dump_header(iter, MCP251XFD_DUMP_OBJECT_TYPE_REG, reg);
 }
 

drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c

@@ -397,7 +397,7 @@ mcp251xfd_regmap_crc_read(void *context,
 
 		return err;
 	}
- out:
+out:
 	memcpy(val_buf, buf_rx->data, val_len);
 
 	return 0;

drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c

@@ -206,6 +206,7 @@ mcp251xfd_ring_init_rx(struct mcp251xfd_priv *priv, u16 *base, u8 *fifo_nr)
 	int i, j;
 
 	mcp251xfd_for_each_rx_ring(priv, rx_ring, i) {
+		rx_ring->last_valid = timecounter_read(&priv->tc);
 		rx_ring->head = 0;
 		rx_ring->tail = 0;
 		rx_ring->base = *base;
@@ -485,6 +486,8 @@ int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv)
 		clear_bit(MCP251XFD_FLAGS_FD_MODE, priv->flags);
 	}
 
+	tx_ring->obj_num_shift_to_u8 = BITS_PER_TYPE(tx_ring->obj_num) -
+		ilog2(tx_ring->obj_num);
 	tx_ring->obj_size = tx_obj_size;
 
 	rem = priv->rx_obj_num;
@@ -507,6 +510,8 @@ int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv)
 		}
 
 		rx_ring->obj_num = rx_obj_num;
+		rx_ring->obj_num_shift_to_u8 = BITS_PER_TYPE(rx_ring->obj_num_shift_to_u8) -
+			ilog2(rx_obj_num);
 		rx_ring->obj_size = rx_obj_size;
 		priv->rx[i] = rx_ring;
 	}

drivers/net/can/spi/mcp251xfd/mcp251xfd-rx.c

@@ -2,7 +2,7 @@
 //
 // mcp251xfd - Microchip MCP251xFD Family CAN controller driver
 //
-// Copyright (c) 2019, 2020, 2021 Pengutronix,
+// Copyright (c) 2019, 2020, 2021, 2023 Pengutronix,
 //               Marc Kleine-Budde <kernel@pengutronix.de>
 //
 // Based on:
@@ -16,23 +16,14 @@
 
 #include "mcp251xfd.h"
 
-static inline int
-mcp251xfd_rx_head_get_from_chip(const struct mcp251xfd_priv *priv,
-				const struct mcp251xfd_rx_ring *ring,
-				u8 *rx_head, bool *fifo_empty)
+static inline bool mcp251xfd_rx_fifo_sta_empty(const u32 fifo_sta)
 {
-	u32 fifo_sta;
-	int err;
-
-	err = regmap_read(priv->map_reg, MCP251XFD_REG_FIFOSTA(ring->fifo_nr),
-			  &fifo_sta);
-	if (err)
-		return err;
-
-	*rx_head = FIELD_GET(MCP251XFD_REG_FIFOSTA_FIFOCI_MASK, fifo_sta);
-	*fifo_empty = !(fifo_sta & MCP251XFD_REG_FIFOSTA_TFNRFNIF);
+	return !(fifo_sta & MCP251XFD_REG_FIFOSTA_TFNRFNIF);
+}
 
-	return 0;
+static inline bool mcp251xfd_rx_fifo_sta_full(const u32 fifo_sta)
+{
+	return fifo_sta & MCP251XFD_REG_FIFOSTA_TFERFFIF;
 }
 
 static inline int
@@ -80,29 +71,49 @@ mcp251xfd_check_rx_tail(const struct mcp251xfd_priv *priv,
 }
 
 static int
-mcp251xfd_rx_ring_update(const struct mcp251xfd_priv *priv,
-			 struct mcp251xfd_rx_ring *ring)
+mcp251xfd_get_rx_len(const struct mcp251xfd_priv *priv,
+		     const struct mcp251xfd_rx_ring *ring,
+		     u8 *len_p)
 {
-	u32 new_head;
-	u8 chip_rx_head;
-	bool fifo_empty;
+	const u8 shift = ring->obj_num_shift_to_u8;
+	u8 chip_head, tail, len;
+	u32 fifo_sta;
 	int err;
 
-	err = mcp251xfd_rx_head_get_from_chip(priv, ring, &chip_rx_head,
-					      &fifo_empty);
-	if (err || fifo_empty)
+	err = regmap_read(priv->map_reg, MCP251XFD_REG_FIFOSTA(ring->fifo_nr),
+			  &fifo_sta);
+	if (err)
+		return err;
+
+	if (mcp251xfd_rx_fifo_sta_empty(fifo_sta)) {
+		*len_p = 0;
+		return 0;
+	}
+
+	if (mcp251xfd_rx_fifo_sta_full(fifo_sta)) {
+		*len_p = ring->obj_num;
+		return 0;
+	}
+
+	chip_head = FIELD_GET(MCP251XFD_REG_FIFOSTA_FIFOCI_MASK, fifo_sta);
+
+	err =  mcp251xfd_check_rx_tail(priv, ring);
+	if (err)
 		return err;
+	tail = mcp251xfd_get_rx_tail(ring);
 
-	/* chip_rx_head, is the next RX-Object filled by the HW.
-	 * The new RX head must be >= the old head.
+	/* First shift to full u8. The subtraction works on signed
+	 * values, that keeps the difference steady around the u8
+	 * overflow. The right shift acts on len, which is an u8.
 	 */
-	new_head = round_down(ring->head, ring->obj_num) + chip_rx_head;
-	if (new_head <= ring->head)
-		new_head += ring->obj_num;
+	BUILD_BUG_ON(sizeof(ring->obj_num) != sizeof(chip_head));
+	BUILD_BUG_ON(sizeof(ring->obj_num) != sizeof(tail));
+	BUILD_BUG_ON(sizeof(ring->obj_num) != sizeof(len));
 
-	ring->head = new_head;
+	len = (chip_head << shift) - (tail << shift);
+	*len_p = len >> shift;
 
-	return mcp251xfd_check_rx_tail(priv, ring);
+	return 0;
 }
 
 static void
@@ -148,8 +159,6 @@ mcp251xfd_hw_rx_obj_to_skb(const struct mcp251xfd_priv *priv,
 
 	if (!(hw_rx_obj->flags & MCP251XFD_OBJ_FLAGS_RTR))
 		memcpy(cfd->data, hw_rx_obj->data, cfd->len);
-
-	mcp251xfd_skb_set_timestamp(priv, skb, hw_rx_obj->ts);
 }
 
 static int
@@ -160,8 +169,26 @@ mcp251xfd_handle_rxif_one(struct mcp251xfd_priv *priv,
 	struct net_device_stats *stats = &priv->ndev->stats;
 	struct sk_buff *skb;
 	struct canfd_frame *cfd;
+	u64 timestamp;
 	int err;
 
+	/* According to mcp2518fd erratum DS80000789E 6. the FIFOCI
+	 * bits of a FIFOSTA register, here the RX FIFO head index
+	 * might be corrupted and we might process past the RX FIFO's
+	 * head into old CAN frames.
+	 *
+	 * Compare the timestamp of currently processed CAN frame with
+	 * last valid frame received. Abort with -EBADMSG if an old
+	 * CAN frame is detected.
+	 */
+	timestamp = timecounter_cyc2time(&priv->tc, hw_rx_obj->ts);
+	if (timestamp <= ring->last_valid) {
+		stats->rx_fifo_errors++;
+
+		return -EBADMSG;
+	}
+	ring->last_valid = timestamp;
+
 	if (hw_rx_obj->flags & MCP251XFD_OBJ_FLAGS_FDF)
 		skb = alloc_canfd_skb(priv->ndev, &cfd);
 	else
@@ -172,6 +199,7 @@ mcp251xfd_handle_rxif_one(struct mcp251xfd_priv *priv,
 		return 0;
 	}
 
+	mcp251xfd_skb_set_timestamp(skb, timestamp);
 	mcp251xfd_hw_rx_obj_to_skb(priv, hw_rx_obj, skb);
 	err = can_rx_offload_queue_timestamp(&priv->offload, skb, hw_rx_obj->ts);
 	if (err)
@@ -197,52 +225,81 @@ mcp251xfd_rx_obj_read(const struct mcp251xfd_priv *priv,
 	return err;
 }
 
+static int
+mcp251xfd_handle_rxif_ring_uinc(const struct mcp251xfd_priv *priv,
+				struct mcp251xfd_rx_ring *ring,
+				u8 len)
+{
+	int offset;
+	int err;
+
+	if (!len)
+		return 0;
+
+	ring->head += len;
+
+	/* Increment the RX FIFO tail pointer 'len' times in a
+	 * single SPI message.
+	 *
+	 * Note:
+	 * Calculate offset, so that the SPI transfer ends on
+	 * the last message of the uinc_xfer array, which has
+	 * "cs_change == 0", to properly deactivate the chip
+	 * select.
+	 */
+	offset = ARRAY_SIZE(ring->uinc_xfer) - len;
+	err = spi_sync_transfer(priv->spi,
+				ring->uinc_xfer + offset, len);
+	if (err)
+		return err;
+
+	ring->tail += len;
+
+	return 0;
+}
+
 static int
 mcp251xfd_handle_rxif_ring(struct mcp251xfd_priv *priv,
 			   struct mcp251xfd_rx_ring *ring)
 {
 	struct mcp251xfd_hw_rx_obj_canfd *hw_rx_obj = ring->obj;
-	u8 rx_tail, len;
+	u8 rx_tail, len, l;
 	int err, i;
 
-	err = mcp251xfd_rx_ring_update(priv, ring);
+	err = mcp251xfd_get_rx_len(priv, ring, &len);
 	if (err)
 		return err;
 
-	while ((len = mcp251xfd_get_rx_linear_len(ring))) {
-		int offset;
-
+	while ((l = mcp251xfd_get_rx_linear_len(ring, len))) {
 		rx_tail = mcp251xfd_get_rx_tail(ring);
 
 		err = mcp251xfd_rx_obj_read(priv, ring, hw_rx_obj,
-					    rx_tail, len);
+					    rx_tail, l);
 		if (err)
 			return err;
 
-		for (i = 0; i < len; i++) {
+		for (i = 0; i < l; i++) {
 			err = mcp251xfd_handle_rxif_one(priv, ring,
 							(void *)hw_rx_obj +
 							i * ring->obj_size);
-			if (err)
+
+			/* -EBADMSG means we're affected by mcp2518fd
+			 * erratum DS80000789E 6., i.e. the timestamp
+			 * in the RX object is older that the last
+			 * valid received CAN frame. Don't process any
+			 * further and mark processed frames as good.
+			 */
+			if (err == -EBADMSG)
+				return mcp251xfd_handle_rxif_ring_uinc(priv, ring, i);
+			else if (err)
 				return err;
 		}
 
-		/* Increment the RX FIFO tail pointer 'len' times in a
-		 * single SPI message.
-		 *
-		 * Note:
-		 * Calculate offset, so that the SPI transfer ends on
-		 * the last message of the uinc_xfer array, which has
-		 * "cs_change == 0", to properly deactivate the chip
-		 * select.
-		 */
-		offset = ARRAY_SIZE(ring->uinc_xfer) - len;
-		err = spi_sync_transfer(priv->spi,
-					ring->uinc_xfer + offset, len);
+		err = mcp251xfd_handle_rxif_ring_uinc(priv, ring, l);
 		if (err)
 			return err;
 
-		ring->tail += len;
+		len -= l;
 	}
 
 	return 0;

drivers/net/can/spi/mcp251xfd/mcp251xfd-tef.c

@@ -2,7 +2,7 @@
 //
 // mcp251xfd - Microchip MCP251xFD Family CAN controller driver
 //
-// Copyright (c) 2019, 2020, 2021 Pengutronix,
+// Copyright (c) 2019, 2020, 2021, 2023 Pengutronix,
 //               Marc Kleine-Budde <kernel@pengutronix.de>
 //
 // Based on:
@@ -16,6 +16,11 @@
 
 #include "mcp251xfd.h"
 
+static inline bool mcp251xfd_tx_fifo_sta_full(u32 fifo_sta)
+{
+	return !(fifo_sta & MCP251XFD_REG_FIFOSTA_TFNRFNIF);
+}
+
 static inline int
 mcp251xfd_tef_tail_get_from_chip(const struct mcp251xfd_priv *priv,
 				 u8 *tef_tail)
@@ -55,61 +60,44 @@ static int mcp251xfd_check_tef_tail(const struct mcp251xfd_priv *priv)
 	return 0;
 }
 
-static int
-mcp251xfd_handle_tefif_recover(const struct mcp251xfd_priv *priv, const u32 seq)
-{
-	const struct mcp251xfd_tx_ring *tx_ring = priv->tx;
-	u32 tef_sta;
-	int err;
-
-	err = regmap_read(priv->map_reg, MCP251XFD_REG_TEFSTA, &tef_sta);
-	if (err)
-		return err;
-
-	if (tef_sta & MCP251XFD_REG_TEFSTA_TEFOVIF) {
-		netdev_err(priv->ndev,
-			   "Transmit Event FIFO buffer overflow.\n");
-		return -ENOBUFS;
-	}
-
-	netdev_info(priv->ndev,
-		    "Transmit Event FIFO buffer %s. (seq=0x%08x, tef_tail=0x%08x, tef_head=0x%08x, tx_head=0x%08x).\n",
-		    tef_sta & MCP251XFD_REG_TEFSTA_TEFFIF ?
-		    "full" : tef_sta & MCP251XFD_REG_TEFSTA_TEFNEIF ?
-		    "not empty" : "empty",
-		    seq, priv->tef->tail, priv->tef->head, tx_ring->head);
-
-	/* The Sequence Number in the TEF doesn't match our tef_tail. */
-	return -EAGAIN;
-}
-
 static int
 mcp251xfd_handle_tefif_one(struct mcp251xfd_priv *priv,
 			   const struct mcp251xfd_hw_tef_obj *hw_tef_obj,
 			   unsigned int *frame_len_ptr)
 {
 	struct net_device_stats *stats = &priv->ndev->stats;
+	u32 seq, tef_tail_masked, tef_tail;
 	struct sk_buff *skb;
-	u32 seq, seq_masked, tef_tail_masked, tef_tail;
 
-	seq = FIELD_GET(MCP251XFD_OBJ_FLAGS_SEQ_MCP2518FD_MASK,
+	 /* Use the MCP2517FD mask on the MCP2518FD, too. We only
+	  * compare 7 bits, this is enough to detect old TEF objects.
+	  */
+	seq = FIELD_GET(MCP251XFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK,
 			hw_tef_obj->flags);
-
-	/* Use the MCP2517FD mask on the MCP2518FD, too. We only
-	 * compare 7 bits, this should be enough to detect
-	 * net-yet-completed, i.e. old TEF objects.
-	 */
-	seq_masked = seq &
-		field_mask(MCP251XFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
 	tef_tail_masked = priv->tef->tail &
 		field_mask(MCP251XFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
-	if (seq_masked != tef_tail_masked)
-		return mcp251xfd_handle_tefif_recover(priv, seq);
+
+	/* According to mcp2518fd erratum DS80000789E 6. the FIFOCI
+	 * bits of a FIFOSTA register, here the TX FIFO tail index
+	 * might be corrupted and we might process past the TEF FIFO's
+	 * head into old CAN frames.
+	 *
+	 * Compare the sequence number of the currently processed CAN
+	 * frame with the expected sequence number. Abort with
+	 * -EBADMSG if an old CAN frame is detected.
+	 */
+	if (seq != tef_tail_masked) {
+		netdev_dbg(priv->ndev, "%s: chip=0x%02x ring=0x%02x\n", __func__,
+			   seq, tef_tail_masked);
+		stats->tx_fifo_errors++;
+
+		return -EBADMSG;
+	}
 
 	tef_tail = mcp251xfd_get_tef_tail(priv);
 	skb = priv->can.echo_skb[tef_tail];
 	if (skb)
-		mcp251xfd_skb_set_timestamp(priv, skb, hw_tef_obj->ts);
+		mcp251xfd_skb_set_timestamp_raw(priv, skb, hw_tef_obj->ts);
 	stats->tx_bytes +=
 		can_rx_offload_get_echo_skb_queue_timestamp(&priv->offload,
 							    tef_tail, hw_tef_obj->ts,
@@ -120,28 +108,44 @@ mcp251xfd_handle_tefif_one(struct mcp251xfd_priv *priv,
 	return 0;
 }
 
-static int mcp251xfd_tef_ring_update(struct mcp251xfd_priv *priv)
+static int
+mcp251xfd_get_tef_len(struct mcp251xfd_priv *priv, u8 *len_p)
 {
 	const struct mcp251xfd_tx_ring *tx_ring = priv->tx;
-	unsigned int new_head;
-	u8 chip_tx_tail;
+	const u8 shift = tx_ring->obj_num_shift_to_u8;
+	u8 chip_tx_tail, tail, len;
+	u32 fifo_sta;
 	int err;
 
-	err = mcp251xfd_tx_tail_get_from_chip(priv, &chip_tx_tail);
+	err = regmap_read(priv->map_reg, MCP251XFD_REG_FIFOSTA(priv->tx->fifo_nr),
+			  &fifo_sta);
 	if (err)
 		return err;
 
-	/* chip_tx_tail, is the next TX-Object send by the HW.
-	 * The new TEF head must be >= the old head, ...
+	if (mcp251xfd_tx_fifo_sta_full(fifo_sta)) {
+		*len_p = tx_ring->obj_num;
+		return 0;
+	}
+
+	chip_tx_tail = FIELD_GET(MCP251XFD_REG_FIFOSTA_FIFOCI_MASK, fifo_sta);
+
+	err =  mcp251xfd_check_tef_tail(priv);
+	if (err)
+		return err;
+	tail = mcp251xfd_get_tef_tail(priv);
+
+	/* First shift to full u8. The subtraction works on signed
+	 * values, that keeps the difference steady around the u8
+	 * overflow. The right shift acts on len, which is an u8.
 	 */
-	new_head = round_down(priv->tef->head, tx_ring->obj_num) + chip_tx_tail;
-	if (new_head <= priv->tef->head)
-		new_head += tx_ring->obj_num;
+	BUILD_BUG_ON(sizeof(tx_ring->obj_num) != sizeof(chip_tx_tail));
+	BUILD_BUG_ON(sizeof(tx_ring->obj_num) != sizeof(tail));
+	BUILD_BUG_ON(sizeof(tx_ring->obj_num) != sizeof(len));
 
-	/* ... but it cannot exceed the TX head. */
-	priv->tef->head = min(new_head, tx_ring->head);
+	len = (chip_tx_tail << shift) - (tail << shift);
+	*len_p = len >> shift;
 
-	return mcp251xfd_check_tef_tail(priv);
+	return 0;
 }
 
 static inline int
@@ -182,13 +186,12 @@ int mcp251xfd_handle_tefif(struct mcp251xfd_priv *priv)
 	u8 tef_tail, len, l;
 	int err, i;
 
-	err = mcp251xfd_tef_ring_update(priv);
+	err = mcp251xfd_get_tef_len(priv, &len);
 	if (err)
 		return err;
 
 	tef_tail = mcp251xfd_get_tef_tail(priv);
-	len = mcp251xfd_get_tef_len(priv);
-	l = mcp251xfd_get_tef_linear_len(priv);
+	l = mcp251xfd_get_tef_linear_len(priv, len);
 	err = mcp251xfd_tef_obj_read(priv, hw_tef_obj, tef_tail, l);
 	if (err)
 		return err;
@@ -203,12 +206,12 @@ int mcp251xfd_handle_tefif(struct mcp251xfd_priv *priv)
 		unsigned int frame_len = 0;
 
 		err = mcp251xfd_handle_tefif_one(priv, &hw_tef_obj[i], &frame_len);
-		/* -EAGAIN means the Sequence Number in the TEF
-		 * doesn't match our tef_tail. This can happen if we
-		 * read the TEF objects too early. Leave loop let the
-		 * interrupt handler call us again.
+		/* -EBADMSG means we're affected by mcp2518fd erratum
+		 * DS80000789E 6., i.e. the Sequence Number in the TEF
+		 * doesn't match our tef_tail. Don't process any
+		 * further and mark processed frames as good.
 		 */
-		if (err == -EAGAIN)
+		if (err == -EBADMSG)
 			goto out_netif_wake_queue;
 		if (err)
 			return err;
@@ -216,13 +219,15 @@ int mcp251xfd_handle_tefif(struct mcp251xfd_priv *priv)
 		total_frame_len += frame_len;
 	}
 
- out_netif_wake_queue:
+out_netif_wake_queue:
 	len = i;	/* number of handled goods TEFs */
 	if (len) {
 		struct mcp251xfd_tef_ring *ring = priv->tef;
 		struct mcp251xfd_tx_ring *tx_ring = priv->tx;
 		int offset;
 
+		ring->head += len;
+
 		/* Increment the TEF FIFO tail pointer 'len' times in
 		 * a single SPI message.
 		 *

drivers/net/can/spi/mcp251xfd/mcp251xfd-timestamp.c

@@ -2,7 +2,7 @@
 //
 // mcp251xfd - Microchip MCP251xFD Family CAN controller driver
 //
-// Copyright (c) 2021 Pengutronix,
+// Copyright (c) 2021, 2023 Pengutronix,
 //               Marc Kleine-Budde <kernel@pengutronix.de>
 //
 
@@ -11,20 +11,20 @@
 
 #include "mcp251xfd.h"
 
-static u64 mcp251xfd_timestamp_read(const struct cyclecounter *cc)
+static u64 mcp251xfd_timestamp_raw_read(const struct cyclecounter *cc)
 {
 	const struct mcp251xfd_priv *priv;
-	u32 timestamp = 0;
+	u32 ts_raw = 0;
 	int err;
 
 	priv = container_of(cc, struct mcp251xfd_priv, cc);
-	err = mcp251xfd_get_timestamp(priv, &timestamp);
+	err = mcp251xfd_get_timestamp_raw(priv, &ts_raw);
 	if (err)
 		netdev_err(priv->ndev,
 			   "Error %d while reading timestamp. HW timestamps may be inaccurate.",
 			   err);
 
-	return timestamp;
+	return ts_raw;
 }
 
 static void mcp251xfd_timestamp_work(struct work_struct *work)
@@ -39,28 +39,21 @@ static void mcp251xfd_timestamp_work(struct work_struct *work)
 			      MCP251XFD_TIMESTAMP_WORK_DELAY_SEC * HZ);
 }
 
-void mcp251xfd_skb_set_timestamp(const struct mcp251xfd_priv *priv,
-				 struct sk_buff *skb, u32 timestamp)
-{
-	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
-	u64 ns;
-
-	ns = timecounter_cyc2time(&priv->tc, timestamp);
-	hwtstamps->hwtstamp = ns_to_ktime(ns);
-}
-
 void mcp251xfd_timestamp_init(struct mcp251xfd_priv *priv)
 {
 	struct cyclecounter *cc = &priv->cc;
 
-	cc->read = mcp251xfd_timestamp_read;
+	cc->read = mcp251xfd_timestamp_raw_read;
 	cc->mask = CYCLECOUNTER_MASK(32);
 	cc->shift = 1;
 	cc->mult = clocksource_hz2mult(priv->can.clock.freq, cc->shift);
 
-	timecounter_init(&priv->tc, &priv->cc, ktime_get_real_ns());
-
 	INIT_DELAYED_WORK(&priv->timestamp, mcp251xfd_timestamp_work);
+}
+
+void mcp251xfd_timestamp_start(struct mcp251xfd_priv *priv)
+{
+	timecounter_init(&priv->tc, &priv->cc, ktime_get_real_ns());
 	schedule_delayed_work(&priv->timestamp,
 			      MCP251XFD_TIMESTAMP_WORK_DELAY_SEC * HZ);
 }

drivers/net/can/spi/mcp251xfd/mcp251xfd.h

@@ -2,7 +2,7 @@
  *
  * mcp251xfd - Microchip MCP251xFD Family CAN controller driver
  *
- * Copyright (c) 2019, 2020, 2021 Pengutronix,
+ * Copyright (c) 2019, 2020, 2021, 2023 Pengutronix,
  *               Marc Kleine-Budde <kernel@pengutronix.de>
  * Copyright (c) 2019 Martin Sperl <kernel@martin.sperl.org>
  */
@@ -524,6 +524,7 @@ struct mcp251xfd_tef_ring {
 
 	/* u8 obj_num equals tx_ring->obj_num */
 	/* u8 obj_size equals sizeof(struct mcp251xfd_hw_tef_obj) */
+	/* u8 obj_num_shift_to_u8 equals tx_ring->obj_num_shift_to_u8 */
 
 	union mcp251xfd_write_reg_buf irq_enable_buf;
 	struct spi_transfer irq_enable_xfer;
@@ -542,6 +543,7 @@ struct mcp251xfd_tx_ring {
 	u8 nr;
 	u8 fifo_nr;
 	u8 obj_num;
+	u8 obj_num_shift_to_u8;
 	u8 obj_size;
 
 	struct mcp251xfd_tx_obj obj[MCP251XFD_TX_OBJ_NUM_MAX];
@@ -552,10 +554,14 @@ struct mcp251xfd_rx_ring {
 	unsigned int head;
 	unsigned int tail;
 
+	/* timestamp of the last valid received CAN frame */
+	u64 last_valid;
+
 	u16 base;
 	u8 nr;
 	u8 fifo_nr;
 	u8 obj_num;
+	u8 obj_num_shift_to_u8;
 	u8 obj_size;
 
 	union mcp251xfd_write_reg_buf irq_enable_buf;
@@ -809,10 +815,27 @@ mcp251xfd_spi_cmd_write(const struct mcp251xfd_priv *priv,
 	return data;
 }
 
-static inline int mcp251xfd_get_timestamp(const struct mcp251xfd_priv *priv,
-					  u32 *timestamp)
+static inline int mcp251xfd_get_timestamp_raw(const struct mcp251xfd_priv *priv,
+					      u32 *ts_raw)
+{
+	return regmap_read(priv->map_reg, MCP251XFD_REG_TBC, ts_raw);
+}
+
+static inline void mcp251xfd_skb_set_timestamp(struct sk_buff *skb, u64 ns)
 {
-	return regmap_read(priv->map_reg, MCP251XFD_REG_TBC, timestamp);
+	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
+
+	hwtstamps->hwtstamp = ns_to_ktime(ns);
+}
+
+static inline
+void mcp251xfd_skb_set_timestamp_raw(const struct mcp251xfd_priv *priv,
+				     struct sk_buff *skb, u32 ts_raw)
+{
+	u64 ns;
+
+	ns = timecounter_cyc2time(&priv->tc, ts_raw);
+	mcp251xfd_skb_set_timestamp(skb, ns);
 }
 
 static inline u16 mcp251xfd_get_tef_obj_addr(u8 n)
@@ -861,17 +884,8 @@ static inline u8 mcp251xfd_get_tef_tail(const struct mcp251xfd_priv *priv)
 	return priv->tef->tail & (priv->tx->obj_num - 1);
 }
 
-static inline u8 mcp251xfd_get_tef_len(const struct mcp251xfd_priv *priv)
+static inline u8 mcp251xfd_get_tef_linear_len(const struct mcp251xfd_priv *priv, u8 len)
 {
-	return priv->tef->head - priv->tef->tail;
-}
-
-static inline u8 mcp251xfd_get_tef_linear_len(const struct mcp251xfd_priv *priv)
-{
-	u8 len;
-
-	len = mcp251xfd_get_tef_len(priv);
-
 	return min_t(u8, len, priv->tx->obj_num - mcp251xfd_get_tef_tail(priv));
 }
 
@@ -914,18 +928,9 @@ static inline u8 mcp251xfd_get_rx_tail(const struct mcp251xfd_rx_ring *ring)
 	return ring->tail & (ring->obj_num - 1);
 }
 
-static inline u8 mcp251xfd_get_rx_len(const struct mcp251xfd_rx_ring *ring)
-{
-	return ring->head - ring->tail;
-}
-
 static inline u8
-mcp251xfd_get_rx_linear_len(const struct mcp251xfd_rx_ring *ring)
+mcp251xfd_get_rx_linear_len(const struct mcp251xfd_rx_ring *ring, u8 len)
 {
-	u8 len;
-
-	len = mcp251xfd_get_rx_len(ring);
-
 	return min_t(u8, len, ring->obj_num - mcp251xfd_get_rx_tail(ring));
 }
 
@@ -951,9 +956,8 @@ void mcp251xfd_ring_free(struct mcp251xfd_priv *priv);
 int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv);
 int mcp251xfd_handle_rxif(struct mcp251xfd_priv *priv);
 int mcp251xfd_handle_tefif(struct mcp251xfd_priv *priv);
-void mcp251xfd_skb_set_timestamp(const struct mcp251xfd_priv *priv,
-				 struct sk_buff *skb, u32 timestamp);
 void mcp251xfd_timestamp_init(struct mcp251xfd_priv *priv);
+void mcp251xfd_timestamp_start(struct mcp251xfd_priv *priv);
 void mcp251xfd_timestamp_stop(struct mcp251xfd_priv *priv);
 
 void mcp251xfd_tx_obj_write_sync(struct work_struct *work);

drivers/net/can/usb/gs_usb.c

@@ -40,6 +40,9 @@
 #define USB_ABE_CANDEBUGGER_FD_VENDOR_ID 0x16d0
 #define USB_ABE_CANDEBUGGER_FD_PRODUCT_ID 0x10b8
 
+#define USB_XYLANTA_SAINT3_VENDOR_ID 0x16d0
+#define USB_XYLANTA_SAINT3_PRODUCT_ID 0x0f30
+
 #define GS_USB_ENDPOINT_IN 1
 #define GS_USB_ENDPOINT_OUT 2
 
@@ -1530,6 +1533,8 @@ static const struct usb_device_id gs_usb_table[] = {
 				      USB_CES_CANEXT_FD_PRODUCT_ID, 0) },
 	{ USB_DEVICE_INTERFACE_NUMBER(USB_ABE_CANDEBUGGER_FD_VENDOR_ID,
 				      USB_ABE_CANDEBUGGER_FD_PRODUCT_ID, 0) },
+	{ USB_DEVICE_INTERFACE_NUMBER(USB_XYLANTA_SAINT3_VENDOR_ID,
+				      USB_XYLANTA_SAINT3_PRODUCT_ID, 0) },
 	{} /* Terminating entry */
 };