Hi Oliver,

On 09/22/2011 12:24 PM, Oliver Hartkopp wrote:
> This patch adds support for SJW user settings to not set the synchronization
> jump width (SJW) to 1 in any case when using the in-kernel bittiming
> calculation.
> 
> The ip-tool from iproute2 already supports to pass the user defined SJW
> value. The given SJW value is sanitized with the controller specific sjw_max
> and the calculated tseg2 value. As the SJW can have values up to 4 providing
> this value will lead to the maximum possible SJW automatically. A higher SJW
> allows higher controller oscillator tolerances.
> 
> Signed-off-by: Oliver Hartkopp <[email protected]>
> 
> ---
> 
> diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
> index 9bf1116..25695bd 100644
> --- a/drivers/net/can/dev.c
> +++ b/drivers/net/can/dev.c
> @@ -150,7 +150,19 @@ static int can_calc_bittiming(struct net_device *dev, 
> struct can_bittiming *bt)
>       bt->prop_seg = tseg1 / 2;
>       bt->phase_seg1 = tseg1 - bt->prop_seg;
>       bt->phase_seg2 = tseg2;
> -     bt->sjw = 1;
> +
> +     /* check for sjw user settings */
> +     if (!bt->sjw || !btc->sjw_max)
> +             bt->sjw = 1;
> +     else {
> +             /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
> +             if (bt->sjw > btc->sjw_max)
> +                     bt->sjw = btc->sjw_max;
> +             /* bt->sjw must not be higher than tseg2 */
> +             if (tseg2 < bt->sjw)
> +                     bt->sjw = tseg2;
> +     }
> +


Hm, bt->sjw is always 0 when can_calc_bittiming() is called!? Or have I
missed something.

Wolfgang,
_______________________________________________
Socketcan-core mailing list
[email protected]
https://lists.berlios.de/mailman/listinfo/socketcan-core

Reply via email to