Subject: Re: [PATCH v1 0/2] fix statistics for CAN RTR and Error frames
To:     Vincent Mailhol <mailhol.vincent@wanadoo.fr>,
        Marc Kleine-Budde <mkl@pengutronix.de>,
        linux-can@vger.kernel.org
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev
References: <20211123115333.624335-1-mailhol.vincent@wanadoo.fr>
From:   Oliver Hartkopp <socketcan@hartkopp.net>
Message-ID: <bc682dbe-c74e-cd8a-ab05-78a6b4079ebf@hartkopp.net>
Date:   Tue, 23 Nov 2021 22:10:08 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.14.0
MIME-Version: 1.0
In-Reply-To: <20211123115333.624335-1-mailhol.vincent@wanadoo.fr>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 23.11.21 12:53, Vincent Mailhol wrote:
> There are two common errors which are made when reporting the CAN RX
> statistics:
> 
>    1. Incrementing the "normal" RX stats when receiving an Error
>    frame. Error frames is an abstraction of Socket CAN and does not
>    exist on the wire.
> 
>    2. Counting the length of the Remote Transmission Frames (RTR). The
>    length of an RTR frame is the length of the requested frame not the
>    actual payload. In reality the payload of an RTR frame is always 0
>    bytes long.
> 
> This patch series fix those two issues for all CAN drivers.
> 
> Vincent Mailhol (2):
>    can: do not increase rx statistics when receiving CAN error frames
>    can: do not increase rx_bytes statistics for RTR frames

I would suggest to upstream this change without bringing it to older 
(stable) trees.

It doesn't fix any substantial flaw which needs to be backported IMHO.

Btw. can you please change 'error frames' to 'error message frames'?

We had a discussion some years ago that the 'error frames' are used as 
term inside the CAN protocol.

Thanks,
Oliver


> 
>   drivers/net/can/at91_can.c                      |  9 ++-------
>   drivers/net/can/c_can/c_can_main.c              |  8 ++------
>   drivers/net/can/cc770/cc770.c                   |  6 ++----
>   drivers/net/can/dev/dev.c                       |  4 ----
>   drivers/net/can/dev/rx-offload.c                |  7 +++++--
>   drivers/net/can/grcan.c                         |  3 ++-
>   drivers/net/can/ifi_canfd/ifi_canfd.c           |  8 ++------
>   drivers/net/can/janz-ican3.c                    |  3 ++-
>   drivers/net/can/kvaser_pciefd.c                 |  8 ++------
>   drivers/net/can/m_can/m_can.c                   | 10 ++--------
>   drivers/net/can/mscan/mscan.c                   | 10 ++++++----
>   drivers/net/can/pch_can.c                       |  6 ++----
>   drivers/net/can/peak_canfd/peak_canfd.c         |  7 ++-----
>   drivers/net/can/rcar/rcar_can.c                 |  9 +++------
>   drivers/net/can/rcar/rcar_canfd.c               |  7 ++-----
>   drivers/net/can/sja1000/sja1000.c               |  5 ++---
>   drivers/net/can/slcan.c                         |  3 ++-
>   drivers/net/can/spi/hi311x.c                    |  3 ++-
>   drivers/net/can/spi/mcp251x.c                   |  3 ++-
>   drivers/net/can/sun4i_can.c                     | 10 ++++------
>   drivers/net/can/usb/ems_usb.c                   |  5 ++---
>   drivers/net/can/usb/esd_usb2.c                  |  5 ++---
>   drivers/net/can/usb/etas_es58x/es58x_core.c     |  7 -------
>   .../net/can/usb/kvaser_usb/kvaser_usb_core.c    |  2 --
>   .../net/can/usb/kvaser_usb/kvaser_usb_hydra.c   | 14 ++++----------
>   .../net/can/usb/kvaser_usb/kvaser_usb_leaf.c    |  7 ++-----
>   drivers/net/can/usb/mcba_usb.c                  |  3 ++-
>   drivers/net/can/usb/peak_usb/pcan_usb.c         |  5 ++---
>   drivers/net/can/usb/peak_usb/pcan_usb_fd.c      | 11 ++++-------
>   drivers/net/can/usb/peak_usb/pcan_usb_pro.c     | 11 +++++------
>   drivers/net/can/usb/ucan.c                      |  7 +++++--
>   drivers/net/can/usb/usb_8dev.c                  | 10 ++++------
>   drivers/net/can/xilinx_can.c                    | 17 ++++++-----------
>   33 files changed, 86 insertions(+), 147 deletions(-)
>