From: Vincent Mailhol The CAN-FD section of can.rst still states that there is a 1:1 mapping between the Classical CAN DLC and its length. This is only true for the DLC values up to 8. Beyond that point, the length remains at 8. For reference, the mapping between the CAN DLC and the length is given in below table [1]: DLC value CBFF and CEFF FBFF and FEFF [decimal] [byte] [byte] ---------------------------------------------- 0 0 0 1 1 1 2 2 2 3 3 3 4 4 4 5 5 5 6 6 6 7 7 7 8 8 8 9 8 12 10 8 16 11 8 20 12 8 24 13 8 32 14 8 48 15 8 64 Remove the erroneous statement. Instead just state that the length of a Classical CAN frame ranges from 0 to 8. [1] ISO 11898-1:2024, Table 5 -- DLC: coding of the four LSB Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20251012-can-fd-doc-v1-1-86cc7d130026@kernel.org Signed-off-by: Marc Kleine-Budde --- Documentation/networking/can.rst | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/Documentation/networking/can.rst b/Documentation/networking/can.rst index 7650c4b5be5f..ccd321d29a8a 100644 --- a/Documentation/networking/can.rst +++ b/Documentation/networking/can.rst @@ -1398,10 +1398,9 @@ second bit timing has to be specified in order to enable the CAN FD bitrate. Additionally CAN FD capable CAN controllers support up to 64 bytes of payload. The representation of this length in can_frame.len and canfd_frame.len for userspace applications and inside the Linux network -layer is a plain value from 0 .. 64 instead of the CAN 'data length code'. -The data length code was a 1:1 mapping to the payload length in the Classical -CAN frames anyway. The payload length to the bus-relevant DLC mapping is -only performed inside the CAN drivers, preferably with the helper +layer is a plain value from 0 .. 64 instead of the Classical CAN length +which ranges from 0 to 8. The payload length to the bus-relevant DLC mapping +is only performed inside the CAN drivers, preferably with the helper functions can_fd_dlc2len() and can_fd_len2dlc(). The CAN netdevice driver capabilities can be distinguished by the network -- 2.51.0