Re: [PATCH 2/2] can: add Transmitter Delay Compensation (TDC) documentation

From: Vincent Mailhol

Date: Sun Oct 12 2025 - 12:01:18 EST


Hi Andrew,

On 12/10/2025 at 23:47, Andrew Lunn wrote:
> On Sun, Oct 12, 2025 at 08:23:43PM +0900, Vincent Mailhol wrote:
>> Back in 2021, support for CAN TDC was added to the kernel in series [1]
>> and in iproute2 in series [2]. However, the documentation was never
>> updated.
>
> Hi Vincent
>
> I also don't see anything in man ip-link, nor ip link help. Maybe you
> can add this documentation as well?

The help is indeed not directly visible. But I think this is intended
because can is a sub type. The can is simply listed in man ip-link
under the Link types enumeration.

The can help then be obtain by providing that can type:

$ ip link help can
Usage: ip link set DEVICE type can
[ bitrate BITRATE [ sample-point SAMPLE-POINT] ] |
[ tq TQ prop-seg PROP_SEG phase-seg1 PHASE-SEG1
phase-seg2 PHASE-SEG2 [ sjw SJW ] ]

[ dbitrate BITRATE [ dsample-point SAMPLE-POINT] ] |
[ dtq TQ dprop-seg PROP_SEG dphase-seg1 PHASE-SEG1
dphase-seg2 PHASE-SEG2 [ dsjw SJW ] ]
[ tdcv TDCV tdco TDCO tdcf TDCF ]

[ loopback { on | off } ]
[ listen-only { on | off } ]
[ triple-sampling { on | off } ]
[ one-shot { on | off } ]
[ berr-reporting { on | off } ]
[ fd { on | off } ]
[ fd-non-iso { on | off } ]
[ presume-ack { on | off } ]
[ cc-len8-dlc { on | off } ]
[ tdc-mode { auto | manual | off } ]

[ restart-ms TIME-MS ]
[ restart ]

[ termination { 0..65535 } ]

Where: BITRATE := { NUMBER in bps }
SAMPLE-POINT := { 0.000..0.999 }
TQ := { NUMBER in ns }
PROP-SEG := { NUMBER in tq }
PHASE-SEG1 := { NUMBER in tq }
PHASE-SEG2 := { NUMBER in tq }
SJW := { NUMBER in tq }
TDCV := { NUMBER in tc }
TDCO := { NUMBER in tc }
TDCF := { NUMBER in tc }
RESTART-MS := { 0 | NUMBER in ms }

Does this make sense?


Yours sincerely,
Vincent Mailhol