[PATCH v2 2/5] can: kvaser_usb: do not increase tx statistics when sending error message frames
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STALE1784d
SUPERSEDED
From: Vincent Mailhol <hidden>
Date: 2021-11-25 17:23:25
Also in:
linux-arm-kernel, linux-can, linux-sunxi, lkml
Subsystem:
can network drivers, the rest · Maintainers:
Marc Kleine-Budde, Vincent Mailhol, Linus Torvalds
Revision v2 of 4 in this series.
Revisions (4)
- v2 current
- v3 [diff vs current]
- v4 [diff vs current]
- v5 [diff vs current]
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 tx_packets and tx_bytes fields of struct net_device_stats when sending an error message frame because no actual payload will be transmitted on the wire. N.B. Sending error message frames is a very specific feature which, at the moment, is only supported by the Kvaser Hydra hardware. Please refer to [1] for more details on the topic. [1] https://lore.kernel.org/linux-can/CAMZ6RqK0rTNg3u3mBpZOoY51jLZ-et-J01tY6-+mWsM4meVw-A@mail.gmail.com/t/#u (local) CC: Jimmy Assarsson <redacted> Signed-off-by: Vincent Mailhol <redacted> --- .../net/can/usb/kvaser_usb/kvaser_usb_hydra.c | 22 +++++++++++++------ 1 file changed, 15 insertions(+), 7 deletions(-)
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 3398da323126..32fe352dabeb 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c@@ -1111,8 +1111,10 @@ static void kvaser_usb_hydra_tx_acknowledge(const struct kvaser_usb *dev, { struct kvaser_usb_tx_urb_context *context; struct kvaser_usb_net_priv *priv; + struct can_frame *cf; unsigned long irq_flags; - bool one_shot_fail = false; + int len; + bool one_shot_fail = false, is_err_frame = false; u16 transid = kvaser_usb_hydra_get_cmd_transid(cmd); priv = kvaser_usb_hydra_net_priv_from_cmd(dev, cmd);
@@ -1134,21 +1136,27 @@ static void kvaser_usb_hydra_tx_acknowledge(const struct kvaser_usb *dev, } context = &priv->tx_contexts[transid % dev->max_tx_urbs]; - if (!one_shot_fail) { - struct net_device_stats *stats = &priv->netdev->stats; - - stats->tx_packets++; - stats->tx_bytes += can_fd_dlc2len(context->dlc); - } + len = context->dlc; spin_lock_irqsave(&priv->tx_contexts_lock, irq_flags); + cf = (struct can_frame *)priv->can.echo_skb[context->echo_index]->data; + if (cf) + is_err_frame = !!(cf->can_id & CAN_RTR_FLAG); + can_get_echo_skb(priv->netdev, context->echo_index, NULL); context->echo_index = dev->max_tx_urbs; --priv->active_tx_contexts; netif_wake_queue(priv->netdev); spin_unlock_irqrestore(&priv->tx_contexts_lock, irq_flags); + + if (!one_shot_fail && !is_err_frame) { + struct net_device_stats *stats = &priv->netdev->stats; + + stats->tx_packets++; + stats->tx_bytes += len; + } } static void kvaser_usb_hydra_rx_msg_std(const struct kvaser_usb *dev,
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2.32.0