Merge tag 'linux-can-next-for-5.13-20210407' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2021-04-07

this is a pull request of 6 patches for net-next/master.

The first patch targets the CAN driver infrastructure, it improves the
alloc_can{,fd}_skb() function to set the pointer to the CAN frame to
NULL if skb allocation fails.

The next patch adds missing error handling to the m_can driver's RX
path (the code was introduced in -next, no need to backport).

In the next patch an unused constant is removed from an enum in the
c_can driver.

The last 3 patches target the mcp251xfd driver. They add BQL support
and try to work around a sometimes broken CRC when reading the TBC
register.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 90 insertions, 21 deletions

diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
index 8acedd9e63a7..06045f610f0e 100644
--- a/drivers/net/can/c_can/c_can.h
+++ b/drivers/net/can/c_can/c_can.h
@@ -149,7 +149,6 @@ static const u16 __maybe_unused reg_map_d_can[] = {
 };
 
 enum c_can_dev_id {
-	BOSCH_C_CAN_PLATFORM,
 	BOSCH_C_CAN,
 	BOSCH_D_CAN,
 };
diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index 387c0bc0fb9c..61660248c69e 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -183,8 +183,11 @@ struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
 
 	skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
 			       sizeof(struct can_frame));
-	if (unlikely(!skb))
+	if (unlikely(!skb)) {
+		*cf = NULL;
+
 		return NULL;
+	}
 
 	skb->protocol = htons(ETH_P_CAN);
 	skb->pkt_type = PACKET_BROADCAST;
@@ -211,8 +214,11 @@ struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 
 	skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
 			       sizeof(struct canfd_frame));
-	if (unlikely(!skb))
+	if (unlikely(!skb)) {
+		*cfd = NULL;
+
 		return NULL;
+	}
 
 	skb->protocol = htons(ETH_P_CANFD);
 	skb->pkt_type = PACKET_BROADCAST;
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 890ed826a355..34073cd077e4 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -466,10 +466,17 @@ static void m_can_receive_skb(struct m_can_classdev *cdev,
 			      struct sk_buff *skb,
 			      u32 timestamp)
 {
-	if (cdev->is_peripheral)
-		can_rx_offload_queue_sorted(&cdev->offload, skb, timestamp);
-	else
+	if (cdev->is_peripheral) {
+		struct net_device_stats *stats = &cdev->net->stats;
+		int err;
+
+		err = can_rx_offload_queue_sorted(&cdev->offload, skb,
+						  timestamp);
+		if (err)
+			stats->rx_fifo_errors++;
+	} else {
 		netif_receive_skb(skb);
+	}
 }
 
 static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index 142eb4506b55..970dc570e7a5 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -335,6 +335,8 @@ static void mcp251xfd_ring_init(struct mcp251xfd_priv *priv)
 	u8 len;
 	int i, j;
 
+	netdev_reset_queue(priv->ndev);
+
 	/* TEF */
 	tef_ring = priv->tef;
 	tef_ring->head = 0;
@@ -1262,7 +1264,8 @@ mcp251xfd_handle_tefif_recover(const struct mcp251xfd_priv *priv, const u32 seq)
 
 static int
 mcp251xfd_handle_tefif_one(struct mcp251xfd_priv *priv,
-			   const struct mcp251xfd_hw_tef_obj *hw_tef_obj)
+			   const struct mcp251xfd_hw_tef_obj *hw_tef_obj,
+			   unsigned int *frame_len_ptr)
 {
 	struct net_device_stats *stats = &priv->ndev->stats;
 	struct sk_buff *skb;
@@ -1288,8 +1291,8 @@ mcp251xfd_handle_tefif_one(struct mcp251xfd_priv *priv,
 		mcp251xfd_skb_set_timestamp(priv, skb, hw_tef_obj->ts);
 	stats->tx_bytes +=
 		can_rx_offload_get_echo_skb(&priv->offload,
-					    tef_tail,
-					    hw_tef_obj->ts, NULL);
+					    tef_tail, hw_tef_obj->ts,
+					    frame_len_ptr);
 	stats->tx_packets++;
 	priv->tef->tail++;
 
@@ -1347,6 +1350,7 @@ mcp251xfd_tef_obj_read(const struct mcp251xfd_priv *priv,
 static int mcp251xfd_handle_tefif(struct mcp251xfd_priv *priv)
 {
 	struct mcp251xfd_hw_tef_obj hw_tef_obj[MCP251XFD_TX_OBJ_NUM_MAX];
+	unsigned int total_frame_len = 0;
 	u8 tef_tail, len, l;
 	int err, i;
 
@@ -1368,7 +1372,9 @@ static int mcp251xfd_handle_tefif(struct mcp251xfd_priv *priv)
 	}
 
 	for (i = 0; i < len; i++) {
-		err = mcp251xfd_handle_tefif_one(priv, &hw_tef_obj[i]);
+		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
@@ -1378,6 +1384,8 @@ static int mcp251xfd_handle_tefif(struct mcp251xfd_priv *priv)
 			goto out_netif_wake_queue;
 		if (err)
 			return err;
+
+		total_frame_len += frame_len;
 	}
 
  out_netif_wake_queue:
@@ -1403,6 +1411,7 @@ static int mcp251xfd_handle_tefif(struct mcp251xfd_priv *priv)
 			return err;
 
 		tx_ring->tail += len;
+		netdev_completed_queue(priv->ndev, len, total_frame_len);
 
 		err = mcp251xfd_check_tef_tail(priv);
 		if (err)
@@ -2446,6 +2455,7 @@ static netdev_tx_t mcp251xfd_start_xmit(struct sk_buff *skb,
 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
 	struct mcp251xfd_tx_ring *tx_ring = priv->tx;
 	struct mcp251xfd_tx_obj *tx_obj;
+	unsigned int frame_len;
 	u8 tx_head;
 	int err;
 
@@ -2464,7 +2474,10 @@ static netdev_tx_t mcp251xfd_start_xmit(struct sk_buff *skb,
 	if (mcp251xfd_get_tx_free(tx_ring) == 0)
 		netif_stop_queue(ndev);
 
-	can_put_echo_skb(skb, ndev, tx_head, 0);
+	frame_len = can_skb_get_frame_len(skb);
+	err = can_put_echo_skb(skb, ndev, tx_head, frame_len);
+	if (!err)
+		netdev_sent_queue(priv->ndev, frame_len);
 
 	err = mcp251xfd_tx_obj_write(priv, tx_obj);
 	if (err)
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
index 314f868b3465..297491516a26 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
@@ -233,12 +233,30 @@ mcp251xfd_regmap_crc_write(void *context,
 }
 
 static int
+mcp251xfd_regmap_crc_read_check_crc(const struct mcp251xfd_map_buf_crc * const buf_rx,
+				    const struct mcp251xfd_map_buf_crc * const buf_tx,
+				    unsigned int data_len)
+{
+	u16 crc_received, crc_calculated;
+
+	crc_received = get_unaligned_be16(buf_rx->data + data_len);
+	crc_calculated = mcp251xfd_crc16_compute2(&buf_tx->cmd,
+						  sizeof(buf_tx->cmd),
+						  buf_rx->data,
+						  data_len);
+	if (crc_received != crc_calculated)
+		return -EBADMSG;
+
+	return 0;
+}
+
+
+static int
 mcp251xfd_regmap_crc_read_one(struct mcp251xfd_priv *priv,
 			      struct spi_message *msg, unsigned int data_len)
 {
 	const struct mcp251xfd_map_buf_crc *buf_rx = priv->map_buf_crc_rx;
 	const struct mcp251xfd_map_buf_crc *buf_tx = priv->map_buf_crc_tx;
-	u16 crc_received, crc_calculated;
 	int err;
 
 	BUILD_BUG_ON(sizeof(buf_rx->cmd) != sizeof(__be16) + sizeof(u8));
@@ -248,15 +266,7 @@ mcp251xfd_regmap_crc_read_one(struct mcp251xfd_priv *priv,
 	if (err)
 		return err;
 
-	crc_received = get_unaligned_be16(buf_rx->data + data_len);
-	crc_calculated = mcp251xfd_crc16_compute2(&buf_tx->cmd,
-						  sizeof(buf_tx->cmd),
-						  buf_rx->data,
-						  data_len);
-	if (crc_received != crc_calculated)
-		return -EBADMSG;
-
-	return 0;
+	return mcp251xfd_regmap_crc_read_check_crc(buf_rx, buf_tx, data_len);
 }
 
 static int
@@ -311,6 +321,40 @@ mcp251xfd_regmap_crc_read(void *context,
 		if (err != -EBADMSG)
 			return err;
 
+		/* MCP251XFD_REG_TBC is the time base counter
+		 * register. It increments once per SYS clock tick,
+		 * which is 20 or 40 MHz.
+		 *
+		 * Observation shows that if the lowest byte (which is
+		 * transferred first on the SPI bus) of that register
+		 * is 0x00 or 0x80 the calculated CRC doesn't always
+		 * match the transferred one.
+		 *
+		 * If the highest bit in the lowest byte is flipped
+		 * the transferred CRC matches the calculated one. We
+		 * assume for now the CRC calculation in the chip
+		 * works on wrong data and the transferred data is
+		 * correct.
+		 */
+		if (reg == MCP251XFD_REG_TBC &&
+		    (buf_rx->data[0] == 0x0 || buf_rx->data[0] == 0x80)) {
+			/* Flip highest bit in lowest byte of le32 */
+			buf_rx->data[0] ^= 0x80;
+
+			/* re-check CRC */
+			err = mcp251xfd_regmap_crc_read_check_crc(buf_rx,
+								  buf_tx,
+								  val_len);
+			if (!err) {
+				/* If CRC is now correct, assume
+				 * transferred data was OK, flip bit
+				 * back to original value.
+				 */
+				buf_rx->data[0] ^= 0x80;
+				goto out;
+			}
+		}
+
 		/* MCP251XFD_REG_OSC is the first ever reg we read from.
 		 *
 		 * The chip may be in deep sleep and this SPI transfer