software node: balance refcount for managed software nodes
software_node_notify(), on KOBJ_REMOVE drops the refcount twice on managed
software nodes, thus leading to underflow errors. Balance the refcount by
bumping it in the device_create_managed_software_node() function.
The error [1] was encountered after adding a .shutdown() op to our
fsl-mc-bus driver.
[1]
pc : refcount_warn_saturate+0xf8/0x150
lr : refcount_warn_saturate+0xf8/0x150
sp :
ffff80001009b920
x29:
ffff80001009b920 x28:
ffff1a2420318000 x27:
0000000000000000
x26:
ffffccac15e7a038 x25:
0000000000000008 x24:
ffffccac168e0030
x23:
ffff1a2428a82000 x22:
0000000000080000 x21:
ffff1a24287b5000
x20:
0000000000000001 x19:
ffff1a24261f4400 x18:
ffffffffffffffff
x17:
6f72645f726f7272 x16:
0000000000000000 x15:
ffff80009009b607
x14:
0000000000000000 x13:
ffffccac16602670 x12:
0000000000000a17
x11:
000000000000035d x10:
ffffccac16602670 x9 :
ffffccac16602670
x8 :
00000000ffffefff x7 :
ffffccac1665a670 x6 :
ffffccac1665a670
x5 :
0000000000000000 x4 :
0000000000000000 x3 :
00000000ffffffff
x2 :
0000000000000000 x1 :
0000000000000000 x0 :
ffff1a2420318000
Call trace:
refcount_warn_saturate+0xf8/0x150
kobject_put+0x10c/0x120
software_node_notify+0xd8/0x140
device_platform_notify+0x4c/0xb4
device_del+0x188/0x424
fsl_mc_device_remove+0x2c/0x4c
rebofind sp.c__fsl_mc_device_remove+0x14/0x2c
device_for_each_child+0x5c/0xac
dprc_remove+0x9c/0xc0
fsl_mc_driver_remove+0x28/0x64
__device_release_driver+0x188/0x22c
device_release_driver+0x30/0x50
bus_remove_device+0x128/0x134
device_del+0x16c/0x424
fsl_mc_bus_remove+0x8c/0x114
fsl_mc_bus_shutdown+0x14/0x20
platform_shutdown+0x28/0x40
device_shutdown+0x15c/0x330
__do_sys_reboot+0x218/0x2a0
__arm64_sys_reboot+0x28/0x34
invoke_syscall+0x48/0x114
el0_svc_common+0x40/0xdc
do_el0_svc+0x2c/0x94
el0_svc+0x2c/0x54
el0t_64_sync_handler+0xa8/0x12c
el0t_64_sync+0x198/0x19c
---[ end trace
32eb1c71c7d86821 ]---
Fixes:
151f6ff78cdf ("software node: Provide replacement for device_add_properties()")
Reported-by: Jon Nettleton <jon@solid-run.com>
Suggested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: 5.12+ <stable@vger.kernel.org> # 5.12+
[ rjw: Fix up the software_node_notify() invocation ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>