From: Claudiu Manoil <claudiu.manoil@nxp.com>
Date: Wed, 22 Jul 2020 17:40:12 +0300
Subject: enetc: Remove the mdio bus on PF probe bailout
Git-commit: 26cb7085c8984e5b71d65c374a135134ed8cabb3
Patch-mainline: 5.8-rc7
References: networking-stable-20_07_29
For ENETC ports that register an external MDIO bus,
the bus doesn't get removed on the error bailout path
of enetc_pf_probe().
This issue became much more visible after recent:
commit 07095c025ac2 ("net: enetc: Use DT protocol information to set up the ports")
Before this commit, one could make probing fail on the error
path only by having register_netdev() fail, which is unlikely.
But after this commit, because it moved the enetc_of_phy_get()
call up in the probing sequence, now we can trigger an mdiobus_free()
bug just by forcing enetc_alloc_msix() to return error, i.e. with the
'pci=nomsi' kernel bootarg (since ENETC relies on MSI support to work),
as the calltrace below shows:
kernel BUG at /home/eiz/work/enetc/net/drivers/net/phy/mdio_bus.c:648!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[...]
Hardware name: LS1028A RDB Board (DT)
pstate: 80000005 (Nzcv daif -PAN -UAO BTYPE=--)
pc : mdiobus_free+0x50/0x58
lr : devm_mdiobus_free+0x14/0x20
[...]
Call trace:
mdiobus_free+0x50/0x58
devm_mdiobus_free+0x14/0x20
release_nodes+0x138/0x228
devres_release_all+0x38/0x60
really_probe+0x1c8/0x368
driver_probe_device+0x5c/0xc0
device_driver_attach+0x74/0x80
__driver_attach+0x8c/0xd8
bus_for_each_dev+0x7c/0xd8
driver_attach+0x24/0x30
bus_add_driver+0x154/0x200
driver_register+0x64/0x120
__pci_register_driver+0x44/0x50
enetc_pf_driver_init+0x24/0x30
do_one_initcall+0x60/0x1c0
kernel_init_freeable+0x1fc/0x274
kernel_init+0x14/0x110
ret_from_fork+0x10/0x34
Fixes: ebfcb23d62ab ("enetc: Add ENETC PF level external MDIO support")
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/net/ethernet/freescale/enetc/enetc_pf.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/net/ethernet/freescale/enetc/enetc_pf.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
@@ -935,6 +935,7 @@ static int enetc_pf_probe(struct pci_dev
return 0;
err_reg_netdev:
+ enetc_mdio_remove(pf);
enetc_of_put_phy(priv);
enetc_free_msix(priv);
err_alloc_msix: