From: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx> The function can_calc_tdco() directly retrieves can_priv from the net_device and directly modifies it. This is annoying for the upcoming patch. In drivers/net/can/dev/netlink.c:can_changelink(), the data bittiming are written to a temporary structure and memcpyed to can_priv only after everything succeeded. In the next patch, where we will introduce the netlink interface for TDC parameters, we will add a new TDC block which can potentially fail. For this reason, the data bittiming temporary structure has to be copied after that to-be-introduced TDC block. However, TDC also needs to access data bittiming information. We change the prototype so that the data bittiming structure is passed to can_calc_tdco() as an argument instead of retrieving it from priv. This way can_calc_tdco() can access the data bittiming before it gets memcpyed to priv. Link: https://lore.kernel.org/all/20210918095637.20108-4-mailhol.vincent@xxxxxxxxxx Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- drivers/net/can/dev/bittiming.c | 17 +++++++---------- drivers/net/can/dev/netlink.c | 3 ++- include/linux/can/bittiming.h | 9 +++++++-- 3 files changed, 16 insertions(+), 13 deletions(-) diff --git a/drivers/net/can/dev/bittiming.c b/drivers/net/can/dev/bittiming.c index 0ccf982ca301..0509625c3082 100644 --- a/drivers/net/can/dev/bittiming.c +++ b/drivers/net/can/dev/bittiming.c @@ -175,18 +175,15 @@ int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, return 0; } -void can_calc_tdco(struct net_device *dev) -{ - struct can_priv *priv = netdev_priv(dev); - const struct can_bittiming *dbt = &priv->data_bittiming; - struct can_tdc *tdc = &priv->tdc; - const struct can_tdc_const *tdc_const = priv->tdc_const; +void can_calc_tdco(struct can_tdc *tdc, const struct can_tdc_const *tdc_const, + const struct can_bittiming *dbt, + u32 *ctrlmode, u32 ctrlmode_supported) - if (!tdc_const || - !(priv->ctrlmode_supported & CAN_CTRLMODE_TDC_AUTO)) +{ + if (!tdc_const || !(ctrlmode_supported & CAN_CTRLMODE_TDC_AUTO)) return; - priv->ctrlmode &= ~CAN_CTRLMODE_TDC_MASK; + *ctrlmode &= ~CAN_CTRLMODE_TDC_MASK; /* As specified in ISO 11898-1 section 11.3.3 "Transmitter * delay compensation" (TDC) is only applicable if data BRP is @@ -200,7 +197,7 @@ void can_calc_tdco(struct net_device *dev) if (sample_point_in_tc < tdc_const->tdco_min) return; tdc->tdco = min(sample_point_in_tc, tdc_const->tdco_max); - priv->ctrlmode |= CAN_CTRLMODE_TDC_AUTO; + *ctrlmode |= CAN_CTRLMODE_TDC_AUTO; } } #endif /* CONFIG_CAN_CALC_BITTIMING */ diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c index 80425636049d..e79c9a2ffbfc 100644 --- a/drivers/net/can/dev/netlink.c +++ b/drivers/net/can/dev/netlink.c @@ -189,7 +189,8 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[], memcpy(&priv->data_bittiming, &dbt, sizeof(dbt)); - can_calc_tdco(dev); + can_calc_tdco(&priv->tdc, priv->tdc_const, &priv->data_bittiming, + &priv->ctrlmode, priv->ctrlmode_supported); if (priv->do_set_data_bittiming) { /* Finally, set the bit-timing registers */ diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h index aebbe65dab7e..20b50baf3a02 100644 --- a/include/linux/can/bittiming.h +++ b/include/linux/can/bittiming.h @@ -123,7 +123,9 @@ struct can_tdc_const { int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, const struct can_bittiming_const *btc); -void can_calc_tdco(struct net_device *dev); +void can_calc_tdco(struct can_tdc *tdc, const struct can_tdc_const *tdc_const, + const struct can_bittiming *dbt, + u32 *ctrlmode, u32 ctrlmode_supported); #else /* !CONFIG_CAN_CALC_BITTIMING */ static inline int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, @@ -133,7 +135,10 @@ can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, return -EINVAL; } -static inline void can_calc_tdco(struct net_device *dev) +static inline void +can_calc_tdco(struct can_tdc *tdc, const struct can_tdc_const *tdc_const, + const struct can_bittiming *dbt, + u32 *ctrlmode, u32 ctrlmode_supported) { } #endif /* CONFIG_CAN_CALC_BITTIMING */ -- 2.33.0
