can: do not increase rx_bytes statistics for RTR frames

The actual payload length of the CAN Remote Transmission Request (RTR)
frames is always 0, i.e. no payload is transmitted on the wire.
However, those RTR frames still use the DLC to indicate the length of
the requested frame.

As such, net_device_stats::rx_bytes should not be increased for the
RTR frames.

This patch fixes all the CAN drivers.

Link: https://lore.kernel.org/all/20211207121531.42941-5-mailhol.vincent@wanadoo.fr
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Chandrasekar Ramakrishnan <rcsekar@samsung.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: Yasushi SHOJI <yashi@spacecubics.com>
Cc: Appana Durga Kedareswara rao <appana.durga.rao@xilinx.com>
Cc: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Stephane Grosjean <s.grosjean@peak-system.com>
Tested-by: Jimmy Assarsson <extja@kvaser.com> # kvaser
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Acked-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2
Tested-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/at91_can.c

@@ -617,7 +617,9 @@ static void at91_read_msg(struct net_device *dev, unsigned int mb)
 	at91_read_mb(dev, mb, cf);
 
 	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
+	if (!(cf->can_id & CAN_RTR_FLAG))
+		stats->rx_bytes += cf->len;
+
 	netif_receive_skb(skb);
 
 	can_led_event(dev, CAN_LED_EVENT_RX);

drivers/net/can/c_can/c_can_main.c

@@ -403,10 +403,10 @@ static int c_can_read_msg_object(struct net_device *dev, int iface, u32 ctrl)
 				frame->data[i + 1] = data >> 8;
 			}
 		}
-	}
 
+		stats->rx_bytes += frame->len;
+	}
 	stats->rx_packets++;
-	stats->rx_bytes += frame->len;
 
 	netif_receive_skb(skb);
 	return 0;

drivers/net/can/cc770/cc770.c

@@ -489,10 +489,11 @@ static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1)
 		cf->len = can_cc_dlc2len((config & 0xf0) >> 4);
 		for (i = 0; i < cf->len; i++)
 			cf->data[i] = cc770_read_reg(priv, msgobj[mo].data[i]);
-	}
 
+		stats->rx_bytes += cf->len;
+	}
 	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
+
 	netif_rx(skb);
 }
 

drivers/net/can/dev/rx-offload.c

@@ -56,7 +56,8 @@ static int can_rx_offload_napi_poll(struct napi_struct *napi, int quota)
 		work_done++;
 		if (!(cf->can_id & CAN_ERR_FLAG)) {
 			stats->rx_packets++;
-			stats->rx_bytes += cf->len;
+			if (!(cf->can_id & CAN_RTR_FLAG))
+				stats->rx_bytes += cf->len;
 		}
 		netif_receive_skb(skb);
 	}

drivers/net/can/grcan.c

@@ -1211,11 +1211,11 @@ static int grcan_receive(struct net_device *dev, int budget)
 				shift = GRCAN_MSG_DATA_SHIFT(i);
 				cf->data[i] = (u8)(slot[j] >> shift);
 			}
-		}
 
-		/* Update statistics and read pointer */
+			stats->rx_bytes += cf->len;
+		}
 		stats->rx_packets++;
-		stats->rx_bytes += cf->len;
+
 		netif_receive_skb(skb);
 
 		rd = grcan_ring_add(rd, GRCAN_MSG_SIZE, dma->rx.size);

drivers/net/can/ifi_canfd/ifi_canfd.c

@@ -309,15 +309,15 @@ static void ifi_canfd_read_fifo(struct net_device *ndev)
 			*(u32 *)(cf->data + i) =
 				readl(priv->base + IFI_CANFD_RXFIFO_DATA + i);
 		}
+
+		stats->rx_bytes += cf->len;
 	}
+	stats->rx_packets++;
 
 	/* Remove the packet from FIFO */
 	writel(IFI_CANFD_RXSTCMD_REMOVE_MSG, priv->base + IFI_CANFD_RXSTCMD);
 	writel(rx_irq_mask, priv->base + IFI_CANFD_INTERRUPT);
 
-	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
-
 	netif_receive_skb(skb);
 }
 

drivers/net/can/janz-ican3.c

@@ -1421,7 +1421,8 @@ static int ican3_recv_skb(struct ican3_dev *mod)
 
 	/* update statistics, receive the skb */
 	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
+	if (!(cf->can_id & CAN_RTR_FLAG))
+		stats->rx_bytes += cf->len;
 	netif_receive_skb(skb);
 
 err_noalloc:

drivers/net/can/kvaser_pciefd.c

@@ -1185,20 +1185,21 @@ static int kvaser_pciefd_handle_data_packet(struct kvaser_pciefd *pcie,
 
 	cf->len = can_fd_dlc2len(p->header[1] >> KVASER_PCIEFD_RPACKET_DLC_SHIFT);
 
-	if (p->header[0] & KVASER_PCIEFD_RPACKET_RTR)
+	if (p->header[0] & KVASER_PCIEFD_RPACKET_RTR) {
 		cf->can_id |= CAN_RTR_FLAG;
-	else
+	} else {
 		memcpy(cf->data, data, cf->len);
 
+		stats->rx_bytes += cf->len;
+	}
+	stats->rx_packets++;
+
 	shhwtstamps = skb_hwtstamps(skb);
 
 	shhwtstamps->hwtstamp =
 		ns_to_ktime(div_u64(p->timestamp * 1000,
 				    pcie->freq_to_ticks_div));
 
-	stats->rx_bytes += cf->len;
-	stats->rx_packets++;
-
 	return netif_rx(skb);
 }
 

drivers/net/can/m_can/m_can.c

@@ -518,14 +518,14 @@ static int m_can_read_fifo(struct net_device *dev, u32 rxfs)
 				      cf->data, DIV_ROUND_UP(cf->len, 4));
 		if (err)
 			goto out_free_skb;
+
+		stats->rx_bytes += cf->len;
 	}
+	stats->rx_packets++;
 
 	/* acknowledge rx fifo 0 */
 	m_can_write(cdev, M_CAN_RXF0A, fgi);
 
-	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
-
 	timestamp = FIELD_GET(RX_BUF_RXTS_MASK, fifo_header.dlc);
 
 	m_can_receive_skb(cdev, skb, timestamp);

drivers/net/can/mscan/mscan.c

@@ -404,7 +404,8 @@ static int mscan_rx_poll(struct napi_struct *napi, int quota)
 		if (canrflg & MSCAN_RXF) {
 			mscan_get_rx_frame(dev, frame);
 			stats->rx_packets++;
-			stats->rx_bytes += frame->len;
+			if (!(frame->can_id & CAN_RTR_FLAG))
+				stats->rx_bytes += frame->len;
 		} else if (canrflg & MSCAN_ERR_IF) {
 			mscan_get_err_frame(dev, frame, canrflg);
 		}

drivers/net/can/pch_can.c

@@ -688,12 +688,12 @@ static int pch_can_rx_normal(struct net_device *ndev, u32 obj_num, int quota)
 				cf->data[i] = data_reg;
 				cf->data[i + 1] = data_reg >> 8;
 			}
-		}
 
-		rcv_pkts++;
+			stats->rx_bytes += cf->len;
+		}
 		stats->rx_packets++;
+		rcv_pkts++;
 		quota--;
-		stats->rx_bytes += cf->len;
 		netif_receive_skb(skb);
 
 		pch_fifo_thresh(priv, obj_num);

drivers/net/can/peak_canfd/peak_canfd.c

@@ -310,12 +310,13 @@ static int pucan_handle_can_rx(struct peak_canfd_priv *priv,
 	if (rx_msg_flags & PUCAN_MSG_EXT_ID)
 		cf->can_id |= CAN_EFF_FLAG;
 
-	if (rx_msg_flags & PUCAN_MSG_RTR)
+	if (rx_msg_flags & PUCAN_MSG_RTR) {
 		cf->can_id |= CAN_RTR_FLAG;
-	else
+	} else {
 		memcpy(cf->data, msg->d, cf->len);
 
-	stats->rx_bytes += cf->len;
+		stats->rx_bytes += cf->len;
+	}
 	stats->rx_packets++;
 
 	pucan_netif_rx(skb, msg->ts_low, msg->ts_high);

drivers/net/can/rcar/rcar_can.c

@@ -662,12 +662,13 @@ static void rcar_can_rx_pkt(struct rcar_can_priv *priv)
 		for (dlc = 0; dlc < cf->len; dlc++)
 			cf->data[dlc] =
 			readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].data[dlc]);
+
+		stats->rx_bytes += cf->len;
 	}
+	stats->rx_packets++;
 
 	can_led_event(priv->ndev, CAN_LED_EVENT_RX);
 
-	stats->rx_bytes += cf->len;
-	stats->rx_packets++;
 	netif_receive_skb(skb);
 }
 

drivers/net/can/rcar/rcar_canfd.c

@@ -1550,7 +1550,8 @@ static void rcar_canfd_rx_pkt(struct rcar_canfd_channel *priv)
 
 	can_led_event(priv->ndev, CAN_LED_EVENT_RX);
 
-	stats->rx_bytes += cf->len;
+	if (!(cf->can_id & CAN_RTR_FLAG))
+		stats->rx_bytes += cf->len;
 	stats->rx_packets++;
 	netif_receive_skb(skb);
 }

drivers/net/can/sja1000/sja1000.c

@@ -372,15 +372,16 @@ static void sja1000_rx(struct net_device *dev)
 	} else {
 		for (i = 0; i < cf->len; i++)
 			cf->data[i] = priv->read_reg(priv, dreg++);
+
+		stats->rx_bytes += cf->len;
 	}
+	stats->rx_packets++;
 
 	cf->can_id = id;
 
 	/* release receive buffer */
 	sja1000_write_cmdreg(priv, CMD_RRB);
 
-	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
 	netif_rx(skb);
 
 	can_led_event(dev, CAN_LED_EVENT_RX);

drivers/net/can/slcan.c

@@ -218,7 +218,9 @@ static void slc_bump(struct slcan *sl)
 	skb_put_data(skb, &cf, sizeof(struct can_frame));
 
 	sl->dev->stats.rx_packets++;
-	sl->dev->stats.rx_bytes += cf.len;
+	if (!(cf.can_id & CAN_RTR_FLAG))
+		sl->dev->stats.rx_bytes += cf.len;
+
 	netif_rx_ni(skb);
 }
 

drivers/net/can/spi/hi311x.c

@@ -343,14 +343,15 @@ static void hi3110_hw_rx(struct spi_device *spi)
 	/* Data length */
 	frame->len = can_cc_dlc2len(buf[HI3110_FIFO_WOTIME_DLC_OFF] & 0x0F);
 
-	if (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] & HI3110_FIFO_WOTIME_ID_RTR)
+	if (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] & HI3110_FIFO_WOTIME_ID_RTR) {
 		frame->can_id |= CAN_RTR_FLAG;
-	else
+	} else {
 		memcpy(frame->data, buf + HI3110_FIFO_WOTIME_DAT_OFF,
 		       frame->len);
 
+		priv->net->stats.rx_bytes += frame->len;
+	}
 	priv->net->stats.rx_packets++;
-	priv->net->stats.rx_bytes += frame->len;
 
 	can_led_event(priv->net, CAN_LED_EVENT_RX);
 

drivers/net/can/spi/mcp251x.c

@@ -730,11 +730,12 @@ static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx)
 	}
 	/* Data length */
 	frame->len = can_cc_dlc2len(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
-	if (!(frame->can_id & CAN_RTR_FLAG))
+	if (!(frame->can_id & CAN_RTR_FLAG)) {
 		memcpy(frame->data, buf + RXBDAT_OFF, frame->len);
 
+		priv->net->stats.rx_bytes += frame->len;
+	}
 	priv->net->stats.rx_packets++;
-	priv->net->stats.rx_bytes += frame->len;
 
 	can_led_event(priv->net, CAN_LED_EVENT_RX);
 

drivers/net/can/sun4i_can.c

@@ -501,18 +501,20 @@ static void sun4i_can_rx(struct net_device *dev)
 	}
 
 	/* remote frame ? */
-	if (fi & SUN4I_MSG_RTR_FLAG)
+	if (fi & SUN4I_MSG_RTR_FLAG) {
 		id |= CAN_RTR_FLAG;
-	else
+	} else {
 		for (i = 0; i < cf->len; i++)
 			cf->data[i] = readl(priv->base + dreg + i * 4);
 
+		stats->rx_bytes += cf->len;
+	}
+	stats->rx_packets++;
+
 	cf->can_id = id;
 
 	sun4i_can_write_cmdreg(priv, SUN4I_CMD_RELEASE_RBUF);
 
-	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
 	netif_rx(skb);
 
 	can_led_event(dev, CAN_LED_EVENT_RX);

drivers/net/can/usb/ems_usb.c

@@ -320,10 +320,11 @@ static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
 	} else {
 		for (i = 0; i < cf->len; i++)
 			cf->data[i] = msg->msg.can_msg.msg[i];
-	}
 
+		stats->rx_bytes += cf->len;
+	}
 	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
+
 	netif_rx(skb);
 }
 

drivers/net/can/usb/esd_usb2.c

@@ -332,10 +332,11 @@ static void esd_usb2_rx_can_msg(struct esd_usb2_net_priv *priv,
 		} else {
 			for (i = 0; i < cf->len; i++)
 				cf->data[i] = msg->msg.rx.data[i];
-		}
 
+			stats->rx_bytes += cf->len;
+		}
 		stats->rx_packets++;
-		stats->rx_bytes += cf->len;
+
 		netif_rx(skb);
 	}
 

drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c

@@ -1206,13 +1206,15 @@ static void kvaser_usb_hydra_rx_msg_std(const struct kvaser_usb *dev,
 
 	cf->len = can_cc_dlc2len(cmd->rx_can.dlc);
 
-	if (flags & KVASER_USB_HYDRA_CF_FLAG_REMOTE_FRAME)
+	if (flags & KVASER_USB_HYDRA_CF_FLAG_REMOTE_FRAME) {
 		cf->can_id |= CAN_RTR_FLAG;
-	else
+	} else {
 		memcpy(cf->data, cmd->rx_can.data, cf->len);
 
+		stats->rx_bytes += cf->len;
+	}
 	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
+
 	netif_rx(skb);
 }
 
@@ -1284,13 +1286,15 @@ static void kvaser_usb_hydra_rx_msg_ext(const struct kvaser_usb *dev,
 		cf->len = can_cc_dlc2len(dlc);
 	}
 
-	if (flags & KVASER_USB_HYDRA_CF_FLAG_REMOTE_FRAME)
+	if (flags & KVASER_USB_HYDRA_CF_FLAG_REMOTE_FRAME) {
 		cf->can_id |= CAN_RTR_FLAG;
-	else
+	} else {
 		memcpy(cf->data, cmd->rx_can.kcan_payload, cf->len);
 
+		stats->rx_bytes += cf->len;
+	}
 	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
+
 	netif_rx(skb);
 }
 

drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c

@@ -1068,7 +1068,8 @@ static void kvaser_usb_leaf_rx_can_msg(const struct kvaser_usb *dev,
 	}
 
 	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
+	if (!(cf->can_id & CAN_RTR_FLAG))
+		stats->rx_bytes += cf->len;
 	netif_rx(skb);
 }
 

drivers/net/can/usb/mcba_usb.c

@@ -452,13 +452,14 @@ static void mcba_usb_process_can(struct mcba_priv *priv,
 
 	cf->len = can_cc_dlc2len(msg->dlc & MCBA_DLC_MASK);
 
-	if (msg->dlc & MCBA_DLC_RTR_MASK)
+	if (msg->dlc & MCBA_DLC_RTR_MASK) {
 		cf->can_id |= CAN_RTR_FLAG;
-	else
+	} else {
 		memcpy(cf->data, msg->data, cf->len);
 
+		stats->rx_bytes += cf->len;
+	}
 	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
 
 	can_led_event(priv->netdev, CAN_LED_EVENT_RX);
 	netif_rx(skb);

drivers/net/can/usb/peak_usb/pcan_usb.c

@@ -677,15 +677,16 @@ static int pcan_usb_decode_data(struct pcan_usb_msg_context *mc, u8 status_len)
 		/* Ignore next byte (client private id) if SRR bit is set */
 		if (can_id_flags & PCAN_USB_TX_SRR)
 			mc->ptr++;
+
+		/* update statistics */
+		mc->netdev->stats.rx_bytes += cf->len;
 	}
+	mc->netdev->stats.rx_packets++;
 
 	/* convert timestamp into kernel time */
 	hwts = skb_hwtstamps(skb);
 	peak_usb_get_ts_time(&mc->pdev->time_ref, mc->ts16, &hwts->hwtstamp);
 
-	/* update statistics */
-	mc->netdev->stats.rx_packets++;
-	mc->netdev->stats.rx_bytes += cf->len;
 	/* push the skb */
 	netif_rx(skb);
 

drivers/net/can/usb/peak_usb/pcan_usb_fd.c

@@ -507,13 +507,13 @@ static int pcan_usb_fd_decode_canmsg(struct pcan_usb_fd_if *usb_if,
 	if (rx_msg_flags & PUCAN_MSG_EXT_ID)
 		cfd->can_id |= CAN_EFF_FLAG;
 
-	if (rx_msg_flags & PUCAN_MSG_RTR)
+	if (rx_msg_flags & PUCAN_MSG_RTR) {
 		cfd->can_id |= CAN_RTR_FLAG;
-	else
+	} else {
 		memcpy(cfd->data, rm->d, cfd->len);
-
+		netdev->stats.rx_bytes += cfd->len;
+	}
 	netdev->stats.rx_packets++;
-	netdev->stats.rx_bytes += cfd->len;
 
 	peak_usb_netif_rx_64(skb, le32_to_cpu(rm->ts_low),
 			     le32_to_cpu(rm->ts_high));

drivers/net/can/usb/peak_usb/pcan_usb_pro.c

@@ -536,17 +536,19 @@ static int pcan_usb_pro_handle_canmsg(struct pcan_usb_pro_interface *usb_if,
 	if (rx->flags & PCAN_USBPRO_EXT)
 		can_frame->can_id |= CAN_EFF_FLAG;
 
-	if (rx->flags & PCAN_USBPRO_RTR)
+	if (rx->flags & PCAN_USBPRO_RTR) {
 		can_frame->can_id |= CAN_RTR_FLAG;
-	else
+	} else {
 		memcpy(can_frame->data, rx->data, can_frame->len);
 
+		netdev->stats.rx_bytes += can_frame->len;
+	}
+	netdev->stats.rx_packets++;
+
 	hwts = skb_hwtstamps(skb);
 	peak_usb_get_ts_time(&usb_if->time_ref, le32_to_cpu(rx->ts32),
 			     &hwts->hwtstamp);
 
-	netdev->stats.rx_packets++;
-	netdev->stats.rx_bytes += can_frame->len;
 	netif_rx(skb);
 
 	return 0;

drivers/net/can/usb/ucan.c

@@ -623,7 +623,8 @@ static void ucan_rx_can_msg(struct ucan_priv *up, struct ucan_message_in *m)
 	/* don't count error frames as real packets */
 	if (!(cf->can_id & CAN_ERR_FLAG)) {
 		stats->rx_packets++;
-		stats->rx_bytes += cf->len;
+		if (!(cf->can_id & CAN_RTR_FLAG))
+			stats->rx_bytes += cf->len;
 	}
 
 	/* pass it to Linux */

drivers/net/can/usb/usb_8dev.c

@@ -472,13 +472,14 @@ static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
 		if (msg->flags & USB_8DEV_EXTID)
 			cf->can_id |= CAN_EFF_FLAG;
 
-		if (msg->flags & USB_8DEV_RTR)
+		if (msg->flags & USB_8DEV_RTR) {
 			cf->can_id |= CAN_RTR_FLAG;
-		else
+		} else {
 			memcpy(cf->data, msg->data, cf->len);
-
+			stats->rx_bytes += cf->len;
+		}
 		stats->rx_packets++;
-		stats->rx_bytes += cf->len;
+
 		netif_rx(skb);
 
 		can_led_event(priv->netdev, CAN_LED_EVENT_RX);

drivers/net/can/xilinx_can.c

@@ -787,10 +787,11 @@ static int xcan_rx(struct net_device *ndev, int frame_base)
 			*(__be32 *)(cf->data) = cpu_to_be32(data[0]);
 		if (cf->len > 4)
 			*(__be32 *)(cf->data + 4) = cpu_to_be32(data[1]);
-	}
 
-	stats->rx_bytes += cf->len;
+		stats->rx_bytes += cf->len;
+	}
 	stats->rx_packets++;
+
 	netif_receive_skb(skb);
 
 	return 1;
@@ -871,8 +872,11 @@ static int xcanfd_rx(struct net_device *ndev, int frame_base)
 			*(__be32 *)(cf->data + i) = cpu_to_be32(data[0]);
 		}
 	}
-	stats->rx_bytes += cf->len;
+
+	if (!(cf->can_id & CAN_RTR_FLAG))
+		stats->rx_bytes += cf->len;
 	stats->rx_packets++;
+
 	netif_receive_skb(skb);
 
 	return 1;