Hi Vincent,
I'm a bit late to the party, but shouldn't the patch do that what you promise in
the commit message? See at the end.
Best regards,
Stefan
Am Mittwoch, den 13.07.2022, 00:31 +0900 schrieb Vincent Mailhol:
> Currently, data[5..7] of struct can_frame, when used as a CAN error
> frame, are defined as being "controller specific". Device specific
> behaviours are problematic because it prevents someone from writing
> code which is portable between devices.
>
> As a matter of fact, data[5] is never used, data[6] is always used to
> report TX error counter and data[7] is always used to report RX error
> counter. can-utils also relies on this.
>
> This patch updates the comment in the uapi header to specify that
> data[5] is reserved (and thus should not be used) and that data[6..7]
> are used for error counters.
>
> Fixes: 0d66548a10cb ("[CAN]: Add PF_CAN core module")
> Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
> ---
> include/uapi/linux/can/error.h | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/include/uapi/linux/can/error.h b/include/uapi/linux/can/error.h
> index 34633283de64..4eb7da568dde 100644
> --- a/include/uapi/linux/can/error.h
> +++ b/include/uapi/linux/can/error.h
> @@ -120,6 +120,9 @@
> #define CAN_ERR_TRX_CANL_SHORT_TO_GND 0x70 /* 0111 0000 */
> #define CAN_ERR_TRX_CANL_SHORT_TO_CANH 0x80 /* 1000 0000 */
>
> -/* controller specific additional information / data[5..7] */
> +/* data[5] is reserved (do not use) */
> +
> +/* TX error counter / data[6] */
> +/* TX error counter / data[7] */
/* RX error counter / data[7] */
^
> #endif /* _UAPI_CAN_ERROR_H */
