diff options
| author | Oliver Hartkopp <socketcan@hartkopp.net> | 2025-11-26 11:16:08 +0100 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2025-11-26 11:20:43 +0100 |
| commit | 6df01533e535d21cac779ff35cc25c43304035c3 (patch) | |
| tree | ea4c8abbafe9c498a804784f909bf006a09b0d8b /include/linux/can | |
| parent | 233134af208689c2d5d40896f5740473a74e3cb2 (diff) | |
can: dev: can_dev_dropped_skb: drop CC/FD frames in CANXL-only mode
The error-signalling (ES) is a mandatory functionality for CAN CC and
CAN FD to report CAN frame format violations by sending an error-frame
signal on the bus.
A so-called 'mixed-mode' is intended to have (XL-tolerant) CAN FD nodes
and CAN XL nodes on one CAN segment, where the FD-controllers can talk
CC/FD and the XL-controllers can talk CC/FD/XL. This mixed-mode
utilizes the error-signalling for sending CC/FD/XL frames.
The CANXL-only mode disables the error-signalling in the CAN XL
controller. This mode does not allow CC/FD frames to be sent but
additionally offers a CAN XL transceiver mode switching (TMS).
Configured with CAN_CTRLMODE_FD and CAN_CTRLMODE_XL this leads to:
FD=0 XL=0 CC-only mode (ES=1)
FD=1 XL=0 FD/CC mixed-mode (ES=1)
FD=1 XL=1 XL/FD/CC mixed-mode (ES=1)
FD=0 XL=1 XL-only mode (ES=0, TMS optional)
The helper function can_dev_in_xl_only_mode() determines the required
value to disable error signalling in the CAN XL controller.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-7-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'include/linux/can')
| -rw-r--r-- | include/linux/can/dev.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index f15879bd818d..52c8be5c160e 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -135,6 +135,19 @@ void can_bus_off(struct net_device *dev); const char *can_get_state_str(const enum can_state state); const char *can_get_ctrlmode_str(u32 ctrlmode); +static inline bool can_dev_in_xl_only_mode(struct can_priv *priv) +{ + const u32 mixed_mode = CAN_CTRLMODE_FD | CAN_CTRLMODE_XL; + + /* When CAN XL is enabled but FD is disabled we are running in + * the so-called 'CANXL-only mode' where the error signalling is + * disabled. This helper function determines the required value + * to disable error signalling in the CAN XL controller. + * The so-called CC/FD/XL 'mixed mode' requires error signalling. + */ + return ((priv->ctrlmode & mixed_mode) == CAN_CTRLMODE_XL); +} + /* drop skb if it does not contain a valid CAN frame for sending */ static inline bool can_dev_dropped_skb(struct net_device *dev, struct sk_buff *skb) { @@ -153,6 +166,12 @@ static inline bool can_dev_dropped_skb(struct net_device *dev, struct sk_buff *s goto invalid_skb; } + if (can_dev_in_xl_only_mode(priv) && !can_is_canxl_skb(skb)) { + netdev_info_once(dev, + "Error signaling is disabled, dropping skb\n"); + goto invalid_skb; + } + return can_dropped_invalid_skb(dev, skb); invalid_skb: |