Re: [PATCH v5 1/7] can: netlink: allow user to turn off unsupported features

On 19.08.2021 18:24:27, Vincent MAILHOL wrote:

On Thu. 19 Aug 2021 at 16:45, Marc Kleine-Budde [off-list ref] wrote:

quoted

On 15.08.2021 12:32:42, Vincent Mailhol wrote:

quoted

The sanity checks on the control modes will reject any request related
to an unsupported features, even turning it off.

Example on an interface which does not support CAN-FD:

$ ip link set can0 type can bitrate 500000 fd off
RTNETLINK answers: Operation not supported

This patch lets such command go through (but requests to turn on an
unsupported feature are, of course, still denied).

Signed-off-by: Vincent Mailhol <redacted>

I'm planing to send a pull request to net-next today. I want to do some
more tests with this series

Ack, I am also preparing a new version. But first, I am just
waiting for your reply on the tdc-mode {auto, manual, off}. :)

I want to do some proper testing, if it's now working as I'm expecting,
before continuing the discussion. :D

quoted

but this patch is more or less unrelated,
so I can take it in this PR, should I?

FYI, the reason to add it to the series is that when setting TDC to
off, the ip tool sets both CAN_CTRLMODE_TDC_AUTO and
CAN_CTRLMODE_TDC_MANUAL to zero (which the corresponding bits in
can_ctrlmode::mask set to 1).  Without this patch, netlink would
return -ENOTSUPP if the driver only supported one of
CAN_CTRLMODE_TDC_{AUTO,MANUAL}.

Oh, I see.

Regardless, this patch makes sense as a standalone, I am fine if
you include it in your PR.

Why not, reduces the patch amount on your side :)

Also, if you want, you can include the latest patch of the series as well:
https://lore.kernel.org/linux-can/20210815033248.98111-8-mailhol.vincent@wanadoo.fr/ (local)

It's a comment fix, it should be pretty harmless.

Ok, makes sense.

regards,
Marc

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