Re: [RFC PATCH net-next 1/5] net: dsa: realtek-smi: fix mdio_free bug on module unload
From: Andrew Lunn <andrew@lunn.ch>
Date: 2021-08-22 21:41:25
Also in:
linux-devicetree, lkml
On Sun, Aug 22, 2021 at 09:31:39PM +0200, Alvin Šipraga wrote:
From: Alvin Šipraga <redacted>
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@lunn.ch>
Andrew