can: do not increase rx statistics when generating a CAN rx error message frame

The CAN error message frames (i.e. error skb) are an interface
specific to socket CAN. The payload of the CAN error message frames
does not correspond to any actual data sent on the wire. Only an error
flag and a delimiter are transmitted when an error occurs (c.f. ISO
11898-1 section 10.4.4.2 "Error flag").

For this reason, it makes no sense to increment the rx_packets and
rx_bytes fields of struct net_device_stats because no actual payload
were transmitted on the wire.

This patch fixes all the CAN drivers.

Link: https://lore.kernel.org/all/20211207121531.42941-2-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: 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>

11 files changed, 4 insertions, 36 deletions

diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c
index 2b5302e72435..7cf65936d02e 100644
--- a/drivers/net/can/usb/ems_usb.c
+++ b/drivers/net/can/usb/ems_usb.c
@@ -397,8 +397,6 @@ static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
 		stats->rx_errors++;
 	}
 
-	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 c6068a251fbe..5f6915a27b3d 100644
--- a/drivers/net/can/usb/esd_usb2.c
+++ b/drivers/net/can/usb/esd_usb2.c
@@ -293,8 +293,6 @@ static void esd_usb2_rx_event(struct esd_usb2_net_priv *priv,
 		priv->bec.txerr = txerr;
 		priv->bec.rxerr = rxerr;
 
-		stats->rx_packets++;
-		stats->rx_bytes += cf->len;
 		netif_rx(skb);
 	}
 }
diff --git a/drivers/net/can/usb/etas_es58x/es58x_core.c b/drivers/net/can/usb/etas_es58x/es58x_core.c
index 8508a73d648e..2ed2370a3166 100644
--- a/drivers/net/can/usb/etas_es58x/es58x_core.c
+++ b/drivers/net/can/usb/etas_es58x/es58x_core.c
@@ -849,13 +849,6 @@ int es58x_rx_err_msg(struct net_device *netdev, enum es58x_err error,
 		break;
 	}
 
-	/* driver/net/can/dev.c:can_restart() takes in account error
-	 * messages in the RX stats. Doing the same here for
-	 * consistency.
-	 */
-	netdev->stats.rx_packets++;
-	netdev->stats.rx_bytes += CAN_ERR_DLC;
-
 	if (cf) {
 		if (cf->data[1])
 			cf->can_id |= CAN_ERR_CRTL;
diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
index 0cc0fc866a2a..3e682ef43f8e 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
@@ -279,8 +279,6 @@ int kvaser_usb_can_rx_over_error(struct net_device *netdev)
 	cf->can_id |= CAN_ERR_CRTL;
 	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 
-	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
 	netif_rx(skb);
 
 	return 0;
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 cec36295fdc5..8e2ff08d1083 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
@@ -870,7 +870,6 @@ static void kvaser_usb_hydra_update_state(struct kvaser_usb_net_priv *priv,
 	struct net_device *netdev = priv->netdev;
 	struct can_frame *cf;
 	struct sk_buff *skb;
-	struct net_device_stats *stats;
 	enum can_state new_state, old_state;
 
 	old_state = priv->can.state;
@@ -920,9 +919,6 @@ static void kvaser_usb_hydra_update_state(struct kvaser_usb_net_priv *priv,
 	cf->data[6] = bec->txerr;
 	cf->data[7] = bec->rxerr;
 
-	stats = &netdev->stats;
-	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
 	netif_rx(skb);
 }
 
@@ -1075,8 +1071,6 @@ kvaser_usb_hydra_error_frame(struct kvaser_usb_net_priv *priv,
 	cf->data[6] = bec.txerr;
 	cf->data[7] = bec.rxerr;
 
-	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
 	netif_rx(skb);
 
 	priv->bec.txerr = bec.txerr;
@@ -1110,8 +1104,6 @@ static void kvaser_usb_hydra_one_shot_fail(struct kvaser_usb_net_priv *priv,
 	}
 
 	stats->tx_errors++;
-	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 aed271d5f3bb..d7e8e9b8a7c3 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
@@ -642,8 +642,6 @@ static void kvaser_usb_leaf_tx_acknowledge(const struct kvaser_usb *dev,
 		if (skb) {
 			cf->can_id |= CAN_ERR_RESTARTED;
 
-			stats->rx_packets++;
-			stats->rx_bytes += cf->len;
 			netif_rx(skb);
 		} else {
 			netdev_err(priv->netdev,
@@ -844,8 +842,6 @@ static void kvaser_usb_leaf_rx_error(const struct kvaser_usb *dev,
 	cf->data[6] = es->txerr;
 	cf->data[7] = es->rxerr;
 
-	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
 	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 ac6772fe9746..a59417827168 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb.c
@@ -521,8 +521,6 @@ static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n,
 				     &hwts->hwtstamp);
 	}
 
-	mc->netdev->stats.rx_packets++;
-	mc->netdev->stats.rx_bytes += cf->len;
 	netif_rx(skb);
 
 	return 0;
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 6bd12549f101..185f5a98d217 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
@@ -577,9 +577,6 @@ static int pcan_usb_fd_decode_status(struct pcan_usb_fd_if *usb_if,
 	if (!skb)
 		return -ENOMEM;
 
-	netdev->stats.rx_packets++;
-	netdev->stats.rx_bytes += cf->len;
-
 	peak_usb_netif_rx_64(skb, le32_to_cpu(sm->ts_low),
 			     le32_to_cpu(sm->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 858ab22708fc..f6d19879bf40 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_pro.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_pro.c
@@ -660,8 +660,6 @@ static int pcan_usb_pro_handle_error(struct pcan_usb_pro_interface *usb_if,
 
 	hwts = skb_hwtstamps(skb);
 	peak_usb_get_ts_time(&usb_if->time_ref, le32_to_cpu(er->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 1679cbe45ded..d582c39fc8d0 100644
--- a/drivers/net/can/usb/ucan.c
+++ b/drivers/net/can/usb/ucan.c
@@ -621,8 +621,10 @@ static void ucan_rx_can_msg(struct ucan_priv *up, struct ucan_message_in *m)
 		memcpy(cf->data, m->msg.can_msg.data, cf->len);
 
 	/* don't count error frames as real packets */
-	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
+	if (!(cf->can_id & CAN_ERR_FLAG)) {
+		stats->rx_packets++;
+		stats->rx_bytes += cf->len;
+	}
 
 	/* pass it to Linux */
 	netif_rx(skb);
diff --git a/drivers/net/can/usb/usb_8dev.c b/drivers/net/can/usb/usb_8dev.c
index 1fa02905e7ec..c81ca5e81446 100644
--- a/drivers/net/can/usb/usb_8dev.c
+++ b/drivers/net/can/usb/usb_8dev.c
@@ -447,8 +447,6 @@ static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv,
 	priv->bec.txerr = txerr;
 	priv->bec.rxerr = rxerr;
 
-	stats->rx_packets++;
-	stats->rx_bytes += cf->len;
 	netif_rx(skb);
 }