Commit de82d618 authored by Marc Kleine-Budde's avatar Marc Kleine-Budde
Browse files

can: bittiming: can_fixup_bittiming(): report error via netlink and harmonize error value 

Check each bit timing parameter first individually against their
limits and report a meaningful error message via netlink to the user
space.

In case of an error, return -EINVAL instead of -ERANGE, this
corresponds better to the actual meaning of the error value.

Link: https://lore.kernel.org/all/20230202110854.2318594-12-mkl@pengutronix.de


Suggested-by: default avatarVincent Mailhol <vincent.mailhol@gmail.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 5988bf73

drivers/net/can/dev/bittiming.c

+31 −7
Original line number Diff line number Diff line
@@ -33,22 +33,38 @@ static int can_fixup_bittiming(const struct net_device *dev, struct can_bittimin 
			       const struct can_bittiming_const *btc,

			       struct netlink_ext_ack *extack)

{

	const unsigned int tseg1 = bt->prop_seg + bt->phase_seg1;

	const struct can_priv *priv = netdev_priv(dev);

	unsigned int tseg1;

	u64 brp64;

	int err;



	if (tseg1 < btc->tseg1_min) {

		NL_SET_ERR_MSG_FMT(extack, "prop-seg + phase-seg1: %u less than tseg1-min: %u",

				   tseg1, btc->tseg1_min);

		return -EINVAL;

	}

	if (tseg1 > btc->tseg1_max) {

		NL_SET_ERR_MSG_FMT(extack, "prop-seg + phase-seg1: %u greater than tseg1-max: %u",

				   tseg1, btc->tseg1_max);

		return -EINVAL;

	}

	if (bt->phase_seg2 < btc->tseg2_min) {

		NL_SET_ERR_MSG_FMT(extack, "phase-seg2: %u less than tseg2-min: %u",

				   bt->phase_seg2, btc->tseg2_min);

		return -EINVAL;

	}

	if (bt->phase_seg2 > btc->tseg2_max) {

		NL_SET_ERR_MSG_FMT(extack, "phase-seg2: %u greater than tseg2-max: %u",

				   bt->phase_seg2, btc->tseg2_max);

		return -EINVAL;

	}



	can_sjw_set_default(bt);



	err = can_sjw_check(dev, bt, btc, extack);

	if (err)

		return err;



	tseg1 = bt->prop_seg + bt->phase_seg1;

	if (tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||

	    bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)

		return -ERANGE;



	brp64 = (u64)priv->clock.freq * (u64)bt->tq;

	if (btc->brp_inc > 1)

		do_div(brp64, btc->brp_inc);
@@ -58,8 +74,16 @@ static int can_fixup_bittiming(const struct net_device *dev, struct can_bittimin 
		brp64 *= btc->brp_inc;

	bt->brp = (u32)brp64;



	if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)

	if (bt->brp < btc->brp_min) {

		NL_SET_ERR_MSG_FMT(extack, "resulting brp: %u less than brp-min: %u",

				   bt->brp, btc->brp_min);

		return -EINVAL;

	}

	if (bt->brp > btc->brp_max) {

		NL_SET_ERR_MSG_FMT(extack, "resulting brp: %u greater than brp-max: %u",

				   bt->brp, btc->brp_max);

		return -EINVAL;

	}



	bt->bitrate = priv->clock.freq / (bt->brp * can_bit_time(bt));

	bt->sample_point = ((CAN_SYNC_SEG + tseg1) * 1000) / can_bit_time(bt);