If a driver is removed, the driver framework invokes the driver's remove callback. A CAN driver's remove function calls unregister_candev(), which calls net_device_ops::ndo_stop further down in the call stack for interfaces which are in the "up" state.
With the mcp251xfd driver the removal of the module causes the following warning:
| WARNING: CPU: 0 PID: 352 at net/core/dev.c:7342 __netif_napi_del_locked+0xc8/0xd8
as can_rx_offload_del() deletes the NAPI, while it is still active, because the interface is still up.
To fix the warning, first unregister the network interface, which calls net_device_ops::ndo_stop, which disables the NAPI, and then call can_rx_offload_del().
All other driver using the rx-offload helper have been checked and the same issue has been found in the rockchip and m_can driver. These have been fixed, but only compile time tested. On the mcp251xfd the fix was tested on hardware.
Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- Marc Kleine-Budde (3): can: mcp251xfd: mcp251xfd_remove(): fix order of unregistration calls can: rockchip_canfd: m_can_class_unregister: fix order of unregistration calls can: mcan: m_can_class_unregister: fix order of unregistration calls
drivers/net/can/m_can/m_can.c | 2 +- drivers/net/can/rockchip/rockchip_canfd-core.c | 2 +- drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) --- base-commit: ebd297a2affadb6f6f4d2e5d975c1eda18ac762d change-id: 20250502-can-rx-offload-del-eb79379733dd
Best regards,