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>

10 files changed, 43 insertions, 30 deletions

diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c
index 7cf65936d02e..c9b6adf5c1ec 100644
--- a/drivers/net/can/usb/ems_usb.c
+++ b/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);
 }
 
diff --git a/drivers/net/can/usb/esd_usb2.c b/drivers/net/can/usb/esd_usb2.c
index 5f6915a27b3d..9ac7ee44b6e3 100644
--- a/drivers/net/can/usb/esd_usb2.c
+++ b/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);
 	}
 
diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
index 60e7c5f27a5f..bc902da9c6eb 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
+++ b/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);
 }
 
diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
index d7e8e9b8a7c3..891271af7616 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
+++ b/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);
 }
 
diff --git a/drivers/net/can/usb/mcba_usb.c b/drivers/net/can/usb/mcba_usb.c
index 162d2e11cadd..4d20ea860ea8 100644
--- a/drivers/net/can/usb/mcba_usb.c
+++ b/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);
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb.c b/drivers/net/can/usb/peak_usb/pcan_usb.c
index a59417827168..17dc178f555b 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb.c
+++ b/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);
 
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
index 185f5a98d217..65487ec33566 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
+++ b/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));
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_pro.c b/drivers/net/can/usb/peak_usb/pcan_usb_pro.c
index f6d19879bf40..ebe087f258e3 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_pro.c
+++ b/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;
diff --git a/drivers/net/can/usb/ucan.c b/drivers/net/can/usb/ucan.c
index d582c39fc8d0..388899019955 100644
--- a/drivers/net/can/usb/ucan.c
+++ b/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 */
diff --git a/drivers/net/can/usb/usb_8dev.c b/drivers/net/can/usb/usb_8dev.c
index c81ca5e81446..d0ef1478cf0a 100644
--- a/drivers/net/can/usb/usb_8dev.c
+++ b/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);