From 8e674ca74244eac1cd85c6e9a89b588a03c55ff7 Mon Sep 17 00:00:00 2001
From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Date: Tue, 7 Dec 2021 21:15:30 +0900
Subject: can: do not increase rx_bytes statistics for RTR frames
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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/usb/kvaser_usb/kvaser_usb_hydra.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

(limited to 'drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c')

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);
 }
 
-- 
cgit