On Wed. 16 Jun 2021 à 23:29, Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> wrote: > On 16.06.2021 22:53:02, Vincent MAILHOL wrote: > > On Wed. 16 Jun 2021 at 18:46, Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> wrote: > > > On 04.06.2021 00:15:50, Vincent Mailhol wrote: > > > [...] > > > > > > > +static size_t can_tdc_get_size(const struct net_device *dev) > > > > +{ > > > > + struct can_priv *priv = netdev_priv(dev); > > > > + size_t size; > > > > + > > > > + if (!priv->tdc_const) > > > > + return 0; > > > > + > > > > + size = nla_total_size(0); /* nest IFLA_CAN_TDC */ > > > > + size += nla_total_size(sizeof(u32)); /* IFLA_CAN_TDCV_MAX */ > > > > + size += nla_total_size(sizeof(u32)); /* IFLA_CAN_TDCO_MAX */ > > > > + size += nla_total_size(sizeof(u32)); /* IFLA_CAN_TDCF_MAX */ > > > > + > > > > + if (priv->tdc.tdco) { > > > > > > Naively I'd say, iff the device has tdc_const give the user space the > > > tdc parameters, regardless if some value is 0 or not. > > > > > > What do you think? > > > > I thought about that. > > The first important remark is that if tdc.tdco is zero, then TDC > > is off (c.f. documentation of struct can_tdc::tdco). > > > > Let me illustrate my vision through examples. > > [...] > > examples makes sense \o/ Great! > [...] > > > Finally, I have one side comment. It seems to me that you did not > > understand that the intent of > > | if (priv->tdc.tdco) > > was to actually check whether TDC was on or off. In other words, my > > code was unclear. > > > > I am now thinking to introduce an helper macro: > > static bool can_tdc_is_enabled(const struct can_priv *priv) > > |{ > > | return !!priv->tdc.tdco; > > |} > > > > The code would look more clear like that. > > - if (priv->tdc.tdco) { > > + if (can_tdc_is_enabled(priv) { > > Sounds good, I'm squashing this patch: > > | diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c > | index 6134bbf69c10..d48be574eae7 100644 > | --- a/drivers/net/can/dev/netlink.c > | +++ b/drivers/net/can/dev/netlink.c > | @@ -311,7 +311,7 @@ static size_t can_tdc_get_size(const struct net_device *dev) > | size += nla_total_size(sizeof(u32)); /* IFLA_CAN_TDCO_MAX */ > | size += nla_total_size(sizeof(u32)); /* IFLA_CAN_TDCF_MAX */ > | > | - if (priv->tdc.tdco) { > | + if (can_tdc_is_enabled(priv)) { > | size += nla_total_size(sizeof(u32)); /* IFLA_CAN_TDCV */ > | size += nla_total_size(sizeof(u32)); /* IFLA_CAN_TDCO */ > | size += nla_total_size(sizeof(u32)); /* IFLA_CAN_TDCF */ > | @@ -352,6 +352,7 @@ static size_t can_get_size(const struct net_device *dev) > | priv->data_bitrate_const_cnt); > | size += sizeof(priv->bitrate_max); /* IFLA_CAN_BITRATE_MAX */ > | size += can_tdc_get_size(dev); /* IFLA_CAN_TDC */ > | + > | return size; > | } > | > | @@ -374,7 +375,7 @@ static int can_tdc_fill_info(struct sk_buff *skb, const struct net_device *dev) > | nla_put_u32(skb, IFLA_CAN_TDC_TDCF_MAX, tdc_const->tdcf_max)) > | goto err_cancel; > | > | - if (priv->tdc.tdco) > | + if (can_tdc_is_enabled(priv)) { > | if (nla_put_u32(skb, IFLA_CAN_TDC_TDCV, tdc->tdcv) || > | nla_put_u32(skb, IFLA_CAN_TDC_TDCO, tdc->tdco) || > | nla_put_u32(skb, IFLA_CAN_TDC_TDCF, tdc->tdcf)) > | diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h > | index 9de6e9053e34..b6d1db1e7258 100644 > | --- a/include/linux/can/bittiming.h > | +++ b/include/linux/can/bittiming.h > | @@ -83,6 +83,11 @@ struct can_tdc_const { > | u32 tdcf_max; > | }; > | > | +static inline bool can_tdc_is_enabled(const struct can_priv *priv) Did you try to compile? I am not sure if bittiming.h is able to see struct can_priv which is defined in dev.h. Yours sincerely, Vincent > | +{ > | + return !!priv->tdc.tdco; > | +} > | + > | #ifdef CONFIG_CAN_CALC_BITTIMING > | int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, > | const struct can_bittiming_const *btc);