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.
Signed-off-by: Vincent Mailhol <[email protected]>
---
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 582463bc15f7..d439ea676e6e 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 */
--
2.32.0