As of commit b92143d442 ("net: dsa: mv88e6xxx: add infrastructure for
phylink_pcs") probing of a Marvell 88e6350 switch causes a NULL pointer
de-reference like this example:
...
mv88e6085 d0072004.mdio-mii:11: switch 0x3710 detected: Marvell 88E6350, revision 2
8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 00000000 when read
[00000000] *pgd=00000000
Internal error: Oops: 5 [#1] ARM
Modules linked in:
CPU: 0 PID: 8 Comm: kworker/u2:0 Not tainted 6.7.0-rc2-dirty #26
Hardware name: Marvell Armada 370/XP (Device Tree)
Workqueue: events_unbound deferred_probe_work_func
PC is at mv88e6xxx_port_setup+0x1c/0x44
LR is at dsa_port_devlink_setup+0x74/0x154
pc : [<c057ea24>] lr : [<c0819598>] psr: a0000013
sp : c184fce0 ip : c542b8f4 fp : 00000000
r10: 00000001 r9 : c542a540 r8 : c542bc00
r7 : c542b838 r6 : c5244580 r5 : 00000005 r4 : c5244580
r3 : 00000000 r2 : c542b840 r1 : 00000005 r0 : c1a02040
...
The Marvell 6350 switch has no SERDES interface and so has no
corresponding pcs_ops defined for it. But during probing a call is made
to mv88e6xxx_port_setup() which unconditionally expects pcs_ops to exist -
though the presence of the pcs_ops->pcs_init function is optional.
Modify code to check for pcs_ops first, before checking for and calling
pcs_ops->pcs_init. Modify checking and use of pcs_ops->pcs_teardown
which may potentially suffer the same problem.
Fixes: b92143d442 ("net: dsa: mv88e6xxx: add infrastructure for phylink_pcs")
Signed-off-by: Greg Ungerer <gerg@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
a524eabcd7