From: Vincent Mailhol <mailhol.vincent@wanadoo.fr> To: Marc Kleine-Budde <mkl@pengutronix.de>, linux-can@vger.kernel.org Cc: Oliver Hartkopp <socketcan@hartkopp.net>, Jimmy Assarsson <extja@kvaser.com>, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, Vincent Mailhol <mailhol.vincent@wanadoo.fr> Subject: [PATCH v5 2/5] can: kvaser_usb: do not increase tx statistics when sending error message frames Date: Tue, 7 Dec 2021 21:15:28 +0900 [thread overview] Message-ID: <20211207121531.42941-3-mailhol.vincent@wanadoo.fr> (raw) In-Reply-To: <20211207121531.42941-1-mailhol.vincent@wanadoo.fr> 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 Co-developed-by: Jimmy Assarsson <extja@kvaser.com> Signed-off-by: Jimmy Assarsson <extja@kvaser.com> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> --- drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) 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..75009d38f8e3 100644 --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c @@ -295,6 +295,7 @@ struct kvaser_cmd { #define KVASER_USB_HYDRA_CF_FLAG_OVERRUN BIT(1) #define KVASER_USB_HYDRA_CF_FLAG_REMOTE_FRAME BIT(4) #define KVASER_USB_HYDRA_CF_FLAG_EXTENDED_ID BIT(5) +#define KVASER_USB_HYDRA_CF_FLAG_TX_ACK BIT(6) /* CAN frame flags. Used in ext_rx_can and ext_tx_can */ #define KVASER_USB_HYDRA_CF_FLAG_OSM_NACK BIT(12) #define KVASER_USB_HYDRA_CF_FLAG_ABL BIT(13) @@ -1113,6 +1114,7 @@ static void kvaser_usb_hydra_tx_acknowledge(const struct kvaser_usb *dev, struct kvaser_usb_net_priv *priv; unsigned long irq_flags; bool one_shot_fail = false; + bool is_err_frame = false; u16 transid = kvaser_usb_hydra_get_cmd_transid(cmd); priv = kvaser_usb_hydra_net_priv_from_cmd(dev, cmd); @@ -1131,10 +1133,13 @@ static void kvaser_usb_hydra_tx_acknowledge(const struct kvaser_usb *dev, kvaser_usb_hydra_one_shot_fail(priv, cmd_ext); one_shot_fail = true; } + + is_err_frame = flags & KVASER_USB_HYDRA_CF_FLAG_TX_ACK && + flags & KVASER_USB_HYDRA_CF_FLAG_ERROR_FRAME; } context = &priv->tx_contexts[transid % dev->max_tx_urbs]; - if (!one_shot_fail) { + if (!one_shot_fail && !is_err_frame) { struct net_device_stats *stats = &priv->netdev->stats; stats->tx_packets++; -- 2.32.0
WARNING: multiple messages have this Message-ID (diff)
From: Vincent Mailhol <mailhol.vincent@wanadoo.fr> To: Marc Kleine-Budde <mkl@pengutronix.de>, linux-can@vger.kernel.org Cc: Oliver Hartkopp <socketcan@hartkopp.net>, Jimmy Assarsson <extja@kvaser.com>, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, Vincent Mailhol <mailhol.vincent@wanadoo.fr> Subject: [PATCH v5 2/5] can: kvaser_usb: do not increase tx statistics when sending error message frames Date: Tue, 7 Dec 2021 21:15:28 +0900 [thread overview] Message-ID: <20211207121531.42941-3-mailhol.vincent@wanadoo.fr> (raw) In-Reply-To: <20211207121531.42941-1-mailhol.vincent@wanadoo.fr> 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 Co-developed-by: Jimmy Assarsson <extja@kvaser.com> Signed-off-by: Jimmy Assarsson <extja@kvaser.com> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> --- drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) 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..75009d38f8e3 100644 --- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c +++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c @@ -295,6 +295,7 @@ struct kvaser_cmd { #define KVASER_USB_HYDRA_CF_FLAG_OVERRUN BIT(1) #define KVASER_USB_HYDRA_CF_FLAG_REMOTE_FRAME BIT(4) #define KVASER_USB_HYDRA_CF_FLAG_EXTENDED_ID BIT(5) +#define KVASER_USB_HYDRA_CF_FLAG_TX_ACK BIT(6) /* CAN frame flags. Used in ext_rx_can and ext_tx_can */ #define KVASER_USB_HYDRA_CF_FLAG_OSM_NACK BIT(12) #define KVASER_USB_HYDRA_CF_FLAG_ABL BIT(13) @@ -1113,6 +1114,7 @@ static void kvaser_usb_hydra_tx_acknowledge(const struct kvaser_usb *dev, struct kvaser_usb_net_priv *priv; unsigned long irq_flags; bool one_shot_fail = false; + bool is_err_frame = false; u16 transid = kvaser_usb_hydra_get_cmd_transid(cmd); priv = kvaser_usb_hydra_net_priv_from_cmd(dev, cmd); @@ -1131,10 +1133,13 @@ static void kvaser_usb_hydra_tx_acknowledge(const struct kvaser_usb *dev, kvaser_usb_hydra_one_shot_fail(priv, cmd_ext); one_shot_fail = true; } + + is_err_frame = flags & KVASER_USB_HYDRA_CF_FLAG_TX_ACK && + flags & KVASER_USB_HYDRA_CF_FLAG_ERROR_FRAME; } context = &priv->tx_contexts[transid % dev->max_tx_urbs]; - if (!one_shot_fail) { + if (!one_shot_fail && !is_err_frame) { struct net_device_stats *stats = &priv->netdev->stats; stats->tx_packets++; -- 2.32.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-12-07 12:16 UTC|newest] Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-12-07 12:15 [PATCH v5 0/5] fix statistics and payload issues for error Vincent Mailhol 2021-12-07 12:15 ` Vincent Mailhol 2021-12-07 12:15 ` [PATCH v5 1/5] can: do not increase rx statistics when generating a CAN rx error message frame Vincent Mailhol 2021-12-07 12:15 ` Vincent Mailhol 2021-12-07 12:15 ` Vincent Mailhol [this message] 2021-12-07 12:15 ` [PATCH v5 2/5] can: kvaser_usb: do not increase tx statistics when sending error message frames Vincent Mailhol 2021-12-07 12:15 ` [PATCH v5 3/5] can: do not copy the payload of RTR frames Vincent Mailhol 2021-12-07 12:15 ` Vincent Mailhol 2021-12-10 7:35 ` Marc Kleine-Budde 2021-12-10 7:35 ` Marc Kleine-Budde 2021-12-10 8:02 ` Marc Kleine-Budde 2021-12-10 8:02 ` Marc Kleine-Budde 2021-12-10 8:57 ` Yasushi SHOJI 2021-12-10 8:57 ` Yasushi SHOJI 2021-12-07 12:15 ` [PATCH v5 4/5] can: do not increase rx_bytes statistics for " Vincent Mailhol 2021-12-07 12:15 ` Vincent Mailhol 2021-12-07 12:15 ` [PATCH v5 5/5] can: do not increase tx_bytes " Vincent Mailhol 2021-12-07 12:15 ` Vincent Mailhol 2021-12-08 9:16 ` [PATCH v5 0/5] fix statistics and payload issues for error Marc Kleine-Budde 2021-12-08 9:16 ` Marc Kleine-Budde 2021-12-09 23:21 ` Stefan Mätje 2021-12-09 23:21 ` Stefan Mätje
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