Re: [PATCH 1/3] can: esd_usb: Improved behavior on esd CAN_ERROR_EXT event (1)

[Vincent MAILHOL]

On Tue. 20 Dec. 2022 at 06:25, Frank Jungclaus <frank.jungclaus@xxxxxx> wrote:
>
> Moved the supply for cf->data[3] (bit stream position of CAN error)
> outside of the "switch (ecc & SJA1000_ECC_MASK){}"-statement, because
> this position is independent of the error type.
>
> Fixes: 96d8e90382dc ("can: Add driver for esd CAN-USB/2 device")
> Signed-off-by: Frank Jungclaus <frank.jungclaus@xxxxxx>
> ---
>  drivers/net/can/usb/esd_usb.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/can/usb/esd_usb.c b/drivers/net/can/usb/esd_usb.c
> index 42323f5e6f3a..5e182fadd875 100644
> --- a/drivers/net/can/usb/esd_usb.c
> +++ b/drivers/net/can/usb/esd_usb.c
> @@ -286,7 +286,6 @@ static void esd_usb_rx_event(struct esd_usb_net_priv *priv,
>                                 cf->data[2] |= CAN_ERR_PROT_STUFF;
>                                 break;
>                         default:
> -                               cf->data[3] = ecc & SJA1000_ECC_SEG;
>                                 break;
>                         }
>
> @@ -294,6 +293,9 @@ static void esd_usb_rx_event(struct esd_usb_net_priv *priv,
>                         if (!(ecc & SJA1000_ECC_DIR))
>                                 cf->data[2] |= CAN_ERR_PROT_TX;
>
> +                       /* Bit stream position in CAN frame as the error was detected */
> +                       cf->data[3] = ecc & SJA1000_ECC_SEG;

Can you confirm that the value returned by the device matches the
specifications from linux/can/error.h?

  https://elixir.bootlin.com/linux/latest/source/include/uapi/linux/can/error.h#L90

>                         if (priv->can.state == CAN_STATE_ERROR_WARNING ||
>                             priv->can.state == CAN_STATE_ERROR_PASSIVE) {
>                                 cf->data[1] = (txerr > rxerr) ?
> --
> 2.25.1
>