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From:   Vincent MAILHOL <mailhol.vincent@wanadoo.fr>
Date:   Tue, 14 Dec 2021 10:22:57 +0900
Message-ID: <CAMZ6RqLZA55W-fm3393_Fh-q3sxUpvzFdC+jMTEOo4+9r5yybA@mail.gmail.com>
Subject: Re: [PATCH v6 0/4] report the controller capabilities through the
 netlink interface
To:     Marc Kleine-Budde <mkl@pengutronix.de>, linux-can@vger.kernel.org
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org
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On Tue. 14 Dec 2021 at 01:02, Vincent Mailhol
<mailhol.vincent@wanadoo.fr> wrote:
> The main purpose of this series is to report the CAN controller
> capabilities. The proposed method reuses the existing struct
> can_ctrlmode and thus do not need a new IFLA_CAN_* entry.

I forgot to update this part of the cover letter since v4.
This paragraph is outdated and should now be:

| The main purpose of this series is to report the CAN controller
| capabilities. To do so, a new IFLA_CAN_* entry is
| added: IFLA_CAN_CTRLMODE_EXT. This is done to guarantee forward
| and backward compatibility in the netlink interface.

N.B. I do not plan to send a v7 because the patch descriptions
are correct (only the cover letter was outdated).

> While doing so, I also realized that can_priv::ctrlmode_static could
> actually be derived from the other ctrlmode fields. So I added three
> extra patches to the series: one to replace that field with a
> function, one to add a safeguard on can_set_static_ctrlmode() and one
> to repack struct can_priv and fill the hole created after removing
> can_priv::ctrlmode_priv.
>
> Please note that the first three patches are not required by the
> fourth one. I am just grouping everything in the same series because
> the patches all revolve around the controller modes.
>
>
> ** Changelog **
>
> v5 -> v6:
>
>   - Add back patches 1, 2 and 3 because those were removed from the
>     testing branch of linux-can-next since.
>
>   - Rebase the series on the latest version of net-next.
>
>   - Fix a typo in the comments of the forth patch: guaruanty ->
>     guaranty.
>
> v4 -> v5:
>
>   - Implement IFLA_CAN_CTRLMODE_EXT in order to fix forward
>     compatibility issues as suggested by Marc in:
>     https://lore.kernel.org/linux-can/20211029124608.u7zbprvojifjpa7j@pengutronix.de/T/#m78118c94072083a6f8d2f0f769b120f847ac1384
>
> v3 -> v4:
>
>   - Tag the union in struct can_ctrlmode as packed.
>
>   - Remove patch 1, 2 and 3 from the series because those were already
>     added to the testing branch of linux-can-next (and no changes
>     occurred on those first three patches).
>
> v2 -> v3:
>
>   - Make can_set_static_ctrlmode() return an error and adjust the
>     drivers which use this helper function accordingly.
>
> v1 -> v2:
>
>   - Add a first patch to replace can_priv::ctrlmode_static by the
>     inline function can_get_static_ctrlmode()
>
>   - Add a second patch to reorder the fields of struct can_priv for
>     better packing (save eight bytes on x86_64 \o/)
>
>   - Rewrite the comments of the third patch "can: netlink: report the
>     CAN controller mode supported flags" (no changes on the code
>     itself).
>
> Vincent Mailhol (4):
>   can: dev: replace can_priv::ctrlmode_static by
>     can_get_static_ctrlmode()
>   can: dev: add sanity check in can_set_static_ctrlmode()
>   can: dev: reorder struct can_priv members for better packing
>   can: netlink: report the CAN controller mode supported flags
>
>  drivers/net/can/dev/dev.c         |  5 +++--
>  drivers/net/can/dev/netlink.c     | 33 +++++++++++++++++++++++++++++--
>  drivers/net/can/m_can/m_can.c     | 10 +++++++---
>  drivers/net/can/rcar/rcar_canfd.c |  4 +++-
>  include/linux/can/dev.h           | 24 +++++++++++++++-------
>  include/uapi/linux/can/netlink.h  | 13 ++++++++++++
>  6 files changed, 74 insertions(+), 15 deletions(-)
>
>
> base-commit: 64445dda9d8384975eca54e3f01886fca61e1db6
> prerequisite-patch-id: 84ffb60366d113cfbf6fb8e415217d9e09fadefd
> --
> 2.32.0
>