Commit 676068db authored by Vincent Mailhol's avatar Vincent Mailhol Committed by Marc Kleine-Budde
Browse files

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: default avatarVincent 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: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent e233640c

drivers/net/can/at91_can.c

+0 −6
Original line number Diff line number Diff line
@@ -553,8 +553,6 @@ static void at91_rx_overflow_err(struct net_device *dev) 
	cf->can_id |= CAN_ERR_CRTL;

	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;



	stats->rx_packets++;

	stats->rx_bytes += cf->len;

	netif_receive_skb(skb);

}
@@ -779,8 +777,6 @@ static int at91_poll_err(struct net_device *dev, int quota, u32 reg_sr) 


	at91_poll_err_frame(dev, cf, reg_sr);



	dev->stats.rx_packets++;

	dev->stats.rx_bytes += cf->len;

	netif_receive_skb(skb);



	return 1;
@@ -1037,8 +1033,6 @@ static void at91_irq_err(struct net_device *dev) 


	at91_irq_err_state(dev, cf, new_state);



	dev->stats.rx_packets++;

	dev->stats.rx_bytes += cf->len;

	netif_rx(skb);



	priv->can.state = new_state;

drivers/net/can/c_can/c_can_main.c

+0 −5
Original line number Diff line number Diff line
@@ -920,7 +920,6 @@ static int c_can_handle_state_change(struct net_device *dev, 
	unsigned int reg_err_counter;

	unsigned int rx_err_passive;

	struct c_can_priv *priv = netdev_priv(dev);

	struct net_device_stats *stats = &dev->stats;

	struct can_frame *cf;

	struct sk_buff *skb;

	struct can_berr_counter bec;
@@ -996,8 +995,6 @@ static int c_can_handle_state_change(struct net_device *dev, 
		break;

	}



	stats->rx_packets++;

	stats->rx_bytes += cf->len;

	netif_receive_skb(skb);



	return 1;
@@ -1064,8 +1061,6 @@ static int c_can_handle_bus_err(struct net_device *dev, 
		break;

	}



	stats->rx_packets++;

	stats->rx_bytes += cf->len;

	netif_receive_skb(skb);

	return 1;

}

drivers/net/can/cc770/cc770.c

+0 −3
Original line number Diff line number Diff line
@@ -499,7 +499,6 @@ static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1) 
static int cc770_err(struct net_device *dev, u8 status)

{

	struct cc770_priv *priv = netdev_priv(dev);

	struct net_device_stats *stats = &dev->stats;

	struct can_frame *cf;

	struct sk_buff *skb;

	u8 lec;
@@ -571,8 +570,6 @@ static int cc770_err(struct net_device *dev, u8 status) 
	}





	stats->rx_packets++;

	stats->rx_bytes += cf->len;

	netif_rx(skb);



	return 0;

drivers/net/can/dev/dev.c

+0 −4
Original line number Diff line number Diff line
@@ -136,7 +136,6 @@ EXPORT_SYMBOL_GPL(can_change_state); 
static void can_restart(struct net_device *dev)

{

	struct can_priv *priv = netdev_priv(dev);

	struct net_device_stats *stats = &dev->stats;

	struct sk_buff *skb;

	struct can_frame *cf;

	int err;
@@ -155,9 +154,6 @@ static void can_restart(struct net_device *dev) 


	cf->can_id |= CAN_ERR_RESTARTED;



	stats->rx_packets++;

	stats->rx_bytes += cf->len;



	netif_rx_ni(skb);



restart:

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

+4 −2
Original line number Diff line number Diff line
@@ -54,8 +54,10 @@ static int can_rx_offload_napi_poll(struct napi_struct *napi, int quota) 
		struct can_frame *cf = (struct can_frame *)skb->data;



		work_done++;

		if (!(cf->can_id & CAN_ERR_FLAG)) {

			stats->rx_packets++;

			stats->rx_bytes += cf->len;

		}

		netif_receive_skb(skb);

	}