Re: [RFC PATCH 0/2] can: add dummy_can termination and update SocketCAN docs for CAN XL

[Rakuram Eswaran <rakuram.e96@gmail.com>]

On Tue, 9 Dec 2025 at 21:47, Oliver Hartkopp <socketcan@hartkopp.net> wrote:
>
> Hello Rakuram,
>
> On 08.12.25 15:19, Rakuram Eswaran wrote:
> > On Fri, 28 Nov 2025 at 00:49, Rakuram Eswaran <rakuram.e96@gmail.com> wrote:
> >>
> >> This RFC series introduces two changes related to CAN XL support:
> >>
> >>    1. Add termination configuration support to the dummy_can driver,
> >>       enabling termination testing with iproute2.
> >>
> >>    2. Update the SocketCAN documentation to describe CAN XL operation,
> >>       including MTU changes, bittiming/XBTR settings, mixed-mode
> >>       behaviour, error signalling, and example iproute2 usage.
> >>
> >> The goal of this RFC is to validate whether the proposed behaviour and
> >> documentation match the expectations for the ongoing CAN XL upstream
> >> work. Feedback from the maintainers is highly appreciated.
> >>
> >> Base commit:
> >> commit 30f09200cc4a ("Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux")
> >>
> >> For testing, this series was applied on top of the following patchsets:
> >>
> >>    * "treewide: remove can_change_mtu()" (Vincent Mailhol)
> >>          b4 am 20251003-remove-can_change_mtu-v1-1-337f8bc21181@kernel.org
> >>          git am ./20251003_mailhol_can_treewide_remove_can_change_mtu.mbx
> >>
> >>    * "can: netlink: add CAN XL support" (Marc Kleine-Budde)
> >>          b4 am 20251126-canxl-v8-0-e7e3eb74f889@pengutronix.de
> >>          git am ./v8_20251126_mkl_can_netlink_add_can_xl_support.mbx
> >>
> >> Testing was performed using the iproute2-next tree (canxl-netlink branch),
> >> which contains the required CAN XL netlink support for validating
> >> these changes.
> >>
> >
> > Hello,
> >
> > Gentle ping — any feedback on this documentation update patch series?
>
> Many thanks for the patches.
>
> The termination patch should be commented by Vincent, who is currently
> pretty busy.
>

Understood. I will wait for Vincent’s feedback on the termination patch.

> But as the next merge windows is far away this can be managed in
> January. No hurry.
>
> The documentation is almost fine but still has error-signalling in the
> ip options and there's definitely no xl-cc-len16-dlc option.
>
> Please use the latest iproute2 code to generate the examples:
> https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/
>

Acknowledged. I will update the examples to align with the current iproute2
tree. I will respin the documentation update accordingly and plan to send the
next revision in the first week of January.

Best Regards,
Rakuram