The can_fixup_bittiming() function is used to validate the user-supplied low-level bit timing parameters and calculate the bitrate prescaler (brp) from the requested time quanta (tq) and the CAN clock of the controller. can_fixup_bittiming() selects the best matching integer bit rate prescaler, which may result in a different time quantum than the value specified by the user. Calculate the resulting time quantum and assign it so that the user sees the effective time quantum. Link: https://lore.kernel.org/all/20230202110854.2318594-4-mkl@xxxxxxxxxxxxxx Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- drivers/net/can/dev/bittiming.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/can/dev/bittiming.c b/drivers/net/can/dev/bittiming.c index 5e111dbbe090..e4917c2f34d3 100644 --- a/drivers/net/can/dev/bittiming.c +++ b/drivers/net/can/dev/bittiming.c @@ -40,6 +40,8 @@ static int can_fixup_bittiming(const struct net_device *dev, struct can_bittimin bt->bitrate = priv->clock.freq / (bt->brp * can_bit_time(bt)); bt->sample_point = ((CAN_SYNC_SEG + tseg1) * 1000) / can_bit_time(bt); + bt->tq = DIV_U64_ROUND_CLOSEST(mul_u32_u32(bt->brp, NSEC_PER_SEC), + priv->clock.freq); return 0; } -- 2.39.1