From: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx> Previous patch removed can_priv::ctrlmode_static to replace it with can_get_static_ctrlmode(). A condition sine qua non for this to work is that the controller static modes should never be set in can_priv::ctrlmode_supported (c.f. the comment on can_priv::ctrlmode_supported which states that it is for "options that can be *modified* by netlink"). Also, this condition is already correctly fulfilled by all existing drivers which rely on the ctrlmode_static feature. Nonetheless, we added an extra safeguard in can_set_static_ctrlmode() to return an error value and to warn the developer who would be adventurous enough to set to static a given feature that is already set to supported. The drivers which rely on the static controller mode are then updated to check the return value of can_set_static_ctrlmode(). Link: https://lore.kernel.org/all/20211213160226.56219-3-mailhol.vincent@xxxxxxxxxx Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- drivers/net/can/m_can/m_can.c | 10 +++++++--- drivers/net/can/rcar/rcar_canfd.c | 4 +++- include/linux/can/dev.h | 11 +++++++++-- 3 files changed, 19 insertions(+), 6 deletions(-) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index ae2349420983..5b47cd867783 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -1456,7 +1456,7 @@ static bool m_can_niso_supported(struct m_can_classdev *cdev) static int m_can_dev_setup(struct m_can_classdev *cdev) { struct net_device *dev = cdev->net; - int m_can_version; + int m_can_version, err; m_can_version = m_can_check_core_release(cdev); /* return if unsupported version */ @@ -1486,7 +1486,9 @@ static int m_can_dev_setup(struct m_can_classdev *cdev) switch (cdev->version) { case 30: /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */ - can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO); + err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO); + if (err) + return err; cdev->can.bittiming_const = cdev->bit_timing ? cdev->bit_timing : &m_can_bittiming_const_30X; @@ -1496,7 +1498,9 @@ static int m_can_dev_setup(struct m_can_classdev *cdev) break; case 31: /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */ - can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO); + err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO); + if (err) + return err; cdev->can.bittiming_const = cdev->bit_timing ? cdev->bit_timing : &m_can_bittiming_const_31X; diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c index d0e795f60338..82cc71d5ee10 100644 --- a/drivers/net/can/rcar/rcar_canfd.c +++ b/drivers/net/can/rcar/rcar_canfd.c @@ -1699,7 +1699,9 @@ static int rcar_canfd_channel_probe(struct rcar_canfd_global *gpriv, u32 ch, &rcar_canfd_data_bittiming_const; /* Controller starts in CAN FD only mode */ - can_set_static_ctrlmode(ndev, CAN_CTRLMODE_FD); + err = can_set_static_ctrlmode(ndev, CAN_CTRLMODE_FD); + if (err) + goto fail; priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING; } else { /* Controller starts in Classical CAN only mode */ diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index 92e2d69462f0..fff3f70df697 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -131,17 +131,24 @@ static inline s32 can_get_relative_tdco(const struct can_priv *priv) } /* helper to define static CAN controller features at device creation time */ -static inline void can_set_static_ctrlmode(struct net_device *dev, - u32 static_mode) +static inline int __must_check can_set_static_ctrlmode(struct net_device *dev, + u32 static_mode) { 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 -EINVAL; + } priv->ctrlmode = static_mode; /* override MTU which was set by default in can_setup()? */ if (static_mode & CAN_CTRLMODE_FD) dev->mtu = CANFD_MTU; + + return 0; } static inline u32 can_get_static_ctrlmode(struct can_priv *priv) -- 2.34.1
