Re: [RFC PATCH net-next 1/5] net: dsa: realtek-smi: fix mdio_free bug on module unload

[Andrew Lunn]

On Sun, Aug 22, 2021 at 09:31:39PM +0200, Alvin Šipraga wrote:
> From: Alvin Šipraga <alsi@xxxxxxxxxxxxxxx>
> 
> realtek-smi-core fails to unregister the slave MII bus on module unload,
> raising the following BUG warning:
> 
>     mdio_bus.c:650: BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
> 
>     kernel BUG at drivers/net/phy/mdio_bus.c:650!
>     Internal error: Oops - BUG: 0 [#1] PREEMPT_RT SMP
>     Call trace:
>      mdiobus_free+0x4c/0x50
>      devm_mdiobus_free+0x18/0x20
>      release_nodes.isra.0+0x1c0/0x2b0
>      devres_release_all+0x38/0x58
>      device_release_driver_internal+0x124/0x1e8
>      driver_detach+0x54/0xe0
>      bus_remove_driver+0x60/0xd8
>      driver_unregister+0x34/0x60
>      platform_driver_unregister+0x18/0x20
>      realtek_smi_driver_exit+0x14/0x1c [realtek_smi]
> 
> Fix this by duly unregistering the slave MII bus with
> mdiobus_unregister. We do this in the DSA teardown path, since
> registration is performed in the DSA setup path.

Looking at the setup code, is there anything undoing what
rtl8366rb_setup_cascaded_irq() does?

This patch however loos O.K.

Reviewed-by: Andrew Lunn <andrew@xxxxxxx>

    Andrew