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/
[...]
> 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)
| +{
| + 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);
regards,
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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