[PATCH 0/3] can: rx-offload: fix order of unregistration calls
From: Marc Kleine-Budde
Date: Fri May 02 2025 - 10:15:49 EST
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@xxxxxxxxxxxxxx>
---
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,
--
Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>