The statically enabled features of a CAN controller can be retrieved
using below formula:
| u32 ctrlmode_static = priv->ctrlmode & ~priv->ctrlmode_supported;
As such, there is no need to store this information. This patch remove
the field ctrlmode_static of struct can_priv and provides, in
replacement, the inline function can_get_static_ctrlmode() which
returns the same value.
A condition sine qua non for this to work is that the controller
static modes should never be set in can_priv::ctrlmode_supported. This
is already the case for existing drivers, however, we added a warning
message in can_set_static_ctrlmode() to check that.
Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
---
drivers/net/can/dev/dev.c | 5 +++--
drivers/net/can/dev/netlink.c | 2 +-
include/linux/can/dev.h | 12 ++++++++++--
3 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c
index e3d840b81357..59c79f92fccc 100644
--- a/drivers/net/can/dev/dev.c
+++ b/drivers/net/can/dev/dev.c
@@ -300,6 +300,7 @@ EXPORT_SYMBOL_GPL(free_candev);
int can_change_mtu(struct net_device *dev, int new_mtu)
{
struct can_priv *priv = netdev_priv(dev);
+ u32 ctrlmode_static = can_get_static_ctrlmode(priv);
/* Do not allow changing the MTU while running */
if (dev->flags & IFF_UP)
@@ -309,7 +310,7 @@ int can_change_mtu(struct net_device *dev, int new_mtu)
switch (new_mtu) {
case CAN_MTU:
/* 'CANFD-only' controllers can not switch to CAN_MTU */
- if (priv->ctrlmode_static & CAN_CTRLMODE_FD)
+ if (ctrlmode_static & CAN_CTRLMODE_FD)
return -EINVAL;
priv->ctrlmode &= ~CAN_CTRLMODE_FD;
@@ -318,7 +319,7 @@ int can_change_mtu(struct net_device *dev, int new_mtu)
case CANFD_MTU:
/* check for potential CANFD ability */
if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) &&
- !(priv->ctrlmode_static & CAN_CTRLMODE_FD))
+ !(ctrlmode_static & CAN_CTRLMODE_FD))
return -EINVAL;
priv->ctrlmode |= CAN_CTRLMODE_FD;
diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c
index 80425636049d..6c9906e8040c 100644
--- a/drivers/net/can/dev/netlink.c
+++ b/drivers/net/can/dev/netlink.c
@@ -112,7 +112,7 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[],
if (dev->flags & IFF_UP)
return -EBUSY;
cm = nla_data(data[IFLA_CAN_CTRLMODE]);
- ctrlstatic = priv->ctrlmode_static;
+ ctrlstatic = can_get_static_ctrlmode(priv);
maskedflags = cm->flags & cm->mask;
/* check whether provided bits are allowed to be passed */
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 2413253e54c7..2381ad9e0814 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -69,7 +69,6 @@ struct can_priv {
/* CAN controller features - see include/uapi/linux/can/netlink.h */
u32 ctrlmode; /* current options setting */
u32 ctrlmode_supported; /* options that can be modified by netlink */
- u32 ctrlmode_static; /* static enabled options for driver/hardware */
int restart_ms;
struct delayed_work restart_work;
@@ -104,14 +103,23 @@ static inline void can_set_static_ctrlmode(struct net_device *dev,
struct can_priv *priv = netdev_priv(dev);
/* alloc_candev() succeeded => netdev_priv() is valid at this point */
+ if (priv->ctrlmode_supported & static_mode) {
+ netdev_warn(dev,
+ "Controller features can not be supported and static at the same time\n");
+ return;
+ }
priv->ctrlmode = static_mode;
- priv->ctrlmode_static = static_mode;
/* override MTU which was set by default in can_setup()? */
if (static_mode & CAN_CTRLMODE_FD)
dev->mtu = CANFD_MTU;
}
+static inline u32 can_get_static_ctrlmode(struct can_priv *priv)
+{
+ return priv->ctrlmode & ~priv->ctrlmode_supported;
+}
+
void can_setup(struct net_device *dev);
struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
--
2.32.0
