kernel/linux.git/include/linux/can/dev.h, branch v6.19.11

can: propagate CAN device capabilities via ml_priv

2026-01-15T08:52:04+00:00

Commit 1a620a723853 ("can: raw: instantly reject unsupported CAN frames") caused a sequence of dependency and linker fixes. Instead of accessing CAN device internal data structures which caused the dependency problems this patch introduces capability information into the CAN specific ml_priv data which is accessible from both sides. With this change the CAN network layer can check the required features and the decoupling of the driver layer and network layer is restored. Fixes: 1a620a723853 ("can: raw: instantly reject unsupported CAN frames") Cc: Marc Kleine-Budde Cc: Arnd Bergmann Cc: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260109144135.8495-3-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde

Revert "can: raw: instantly reject unsupported CAN frames"

2026-01-15T08:52:04+00:00

This reverts commit 1a620a723853a0f49703c317d52dc6b9602cbaa8 and its follow-up fixes for the introduced dependency issues. commit 1a620a723853 ("can: raw: instantly reject unsupported CAN frames") commit cb2dc6d2869a ("can: Kconfig: select CAN driver infrastructure by default") commit 6abd4577bccc ("can: fix build dependency") commit 5a5aff6338c0 ("can: fix build dependency") The entire problem was caused by the requirement that a new network layer feature needed to know about the protocol capabilities of the CAN devices. Instead of accessing CAN device internal data structures which caused the dependency problems a better approach has been developed which makes use of CAN specific ml_priv data which is accessible from both sides. Cc: Marc Kleine-Budde Cc: Arnd Bergmann Cc: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260109144135.8495-2-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde

can: Kconfig: select CAN driver infrastructure by default

2025-11-29T12:37:12+00:00

The CAN bus support enabled with CONFIG_CAN provides a socket-based access to CAN interfaces. With the introduction of the latest CAN protocol CAN XL additional configuration status information needs to be exposed to the network layer than formerly provided by standard Linux network drivers. This requires the CAN driver infrastructure to be selected by default. As the CAN network layer can only operate on CAN interfaces anyway all distributions and common default configs enable at least one CAN driver. So selecting CONFIG_CAN_DEV when CONFIG_CAN is selected by the user has no effect on established configurations but solves potential build issues when CONFIG_CAN[_XXX]=y is set together with CANFIG_CAN_DEV=m Fixes: 1a620a723853 ("can: raw: instantly reject unsupported CAN frames") Reported-by: Vincent Mailhol Closes: https://lore.kernel.org/all/CAMZ6RqL_nGszwoLPXn1Li8op-ox4k3Hs6p=Hw6+w0W=DTtobPw@mail.gmail.com/ Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202511280531.YnWW2Rxc-lkp@intel.com/ Closes: https://lore.kernel.org/oe-kbuild-all/202511280842.djCQ0N0O-lkp@intel.com/ Closes: https://lore.kernel.org/oe-kbuild-all/202511282325.uVQFRTkA-lkp@intel.com/ Closes: https://lore.kernel.org/oe-kbuild-all/202511291520.guIE1QHj-lkp@intel.com/ Suggested-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251129090500.17484-1-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde

can: dev: can_dev_dropped_skb: drop CC/FD frames in CANXL-only mode

2025-11-26T10:20:43+00:00

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 Link: https://patch.msgid.link/20251126-canxl-v8-7-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: netlink: add initial CAN XL support

2025-11-26T10:20:43+00:00

CAN XL uses bittiming parameters different from Classical CAN and CAN FD. Thus, all the data bittiming parameters, including TDC, need to be duplicated for CAN XL. Add the CAN XL netlink interface for all the features which are common with CAN FD. Any new CAN XL specific features are added later on. The first time CAN XL is activated, the MTU is set by default to CANXL_MAX_MTU. The user may then configure a custom MTU within the CANXL_MIN_MTU to CANXL_MAX_MTU range, in which case, the custom MTU value will be kept as long as CAN XL remains active. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-5-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: netlink: add CAN_CTRLMODE_RESTRICTED

2025-11-26T10:20:43+00:00

ISO 11898-1:2024 adds a new restricted operation mode. This mode is added as a mandatory feature for nodes which support CAN XL and is retrofitted as optional for legacy nodes (i.e. the ones which only support Classical CAN and CAN FD). The restricted operation mode is nearly the same as the listen only mode: the node can not send data frames or remote frames and can not send dominant bits if an error occurs. The only exception is that the node shall still send the acknowledgment bit. A second niche exception is that the node may still send a data frame containing a time reference message if the node is a primary time provider, but because the time provider feature is not yet implemented in the kernel, this second exception is not relevant to us at the moment. Add the CAN_CTRLMODE_RESTRICTED control mode flag and update the can_dev_dropped_skb() helper function accordingly. Finally, bail out if both CAN_CTRLMODE_LISTENONLY and CAN_CTRLMODE_RESTRICTED are provided. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-4-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: dev: can_dev_dropped_skb: drop CAN FD skbs if FD is off

2025-11-26T10:20:43+00:00

Currently, the CAN FD skb validation logic is based on the MTU: the interface is deemed FD capable if and only if its MTU is greater or equal to CANFD_MTU. This logic is showing its limit with the introduction of CAN XL. For example, consider the two scenarios below: 1. An interface configured with CAN FD on and CAN XL on 2. An interface configured with CAN FD off and CAN XL on In those two scenarios, the interfaces would have the same MTU: CANXL_MTU making it impossible to differentiate which one has CAN FD turned on and which one has it off. Because of the limitation, the only non-UAPI-breaking workaround is to do the check at the device level using the can_priv->ctrlmode flags. Unfortunately, the virtual interfaces (vcan, vxcan), which do not have a can_priv, are left behind. Add a check on the CAN_CTRLMODE_FD flag in can_dev_dropped_skb() and drop FD frames whenever the feature is turned off. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-3-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: convert generic HW timestamp ioctl to ndo_hwtstamp callbacks

2025-10-31T12:12:18+00:00

Can has generic implementation of ndo_eth_ioctl which implements only HW timestamping commands. Implement generic ndo_hwtstamp callbacks and use it in drivers instead of generic ioctl interface. Signed-off-by: Vadim Fedorenko Reviewed-by: Kory Maincent Reviewed-by: Vincent Mailhol Link: https://patch.msgid.link/20251029231620.1135640-2-vadim.fedorenko@linux.dev Signed-off-by: Marc Kleine-Budde

can: treewide: remove can_change_mtu()

2025-10-17T07:57:13+00:00

can_change_mtu() became obsolete by commit 23049938605b ("can: populate the minimum and maximum MTU values"). Now that net_device->min_mtu and net_device->max_mtu are populated, all the checks are already done by dev_validate_mtu() in net/core/dev.c. Remove the net_device_ops->ndo_change_mtu() callback of all the physical interfaces, then remove can_change_mtu(). Only keep the vcan_change_mtu() and vxcan_change_mtu() because the virtual interfaces use their own different MTU logic. The only functional change this patch introduces is that now the user will be able to change the MTU even if the interface is up. This does not matter for Classical CAN and CAN FD because their MTU range is composed of only one value, respectively CAN_MTU and CANFD_MTU. For the upcoming CAN XL, the MTU will be configurable within the CANXL_MIN_MTU to CANXL_MAX_MTU range at any time, even if the interface is up. This is consistent with the other net protocols and does not contradict ISO 11898-1:2024 as having a modifiable MTU is a kernel extension. Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20251003-remove-can_change_mtu-v1-1-337f8bc21181@kernel.org Signed-off-by: Marc Kleine-Budde

can: dev: add can_get_ctrlmode_str()

2025-09-24T15:09:47+00:00

In an effort to give more human readable messages when errors occur because of conflicting options, it can be useful to convert the CAN control mode flags into text. Add a function which converts the first set CAN control mode into a human readable string. The reason to only convert the first one is to simplify edge cases: imagine that there are several invalid control modes, we would just return the first invalid one to the user, thus not having to handle complex string concatenation. The user can then solve the first problem, call the netlink interface again and see the next issue. People who wish to enumerate all the control modes can still do so by, for example, using this new function in a for_each_set_bit() loop. Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-19-e720d28f66fe@kernel.org Signed-off-by: Marc Kleine-Budde