With current extcon_dev_unregister() timing, ida_free is before
device_unregister(), that may cause current id re-alloc to another
device in extcon_dev_register() context but sysfs filename path not
removal completed yet.
The right timing shows below:
on extcon_dev_register: ida_alloc() -> device_register()
on extcon_dev_unregister: device_unregister() -> ida_free()
stack information when an error occurs:
sysfs: cannot create duplicate filename '/class/extcon/extcon1'
Call trace:
sysfs_warn_dup+0x68/0x88
sysfs_do_create_link_sd+0x94/0xdc
sysfs_create_link+0x30/0x48
device_add_class_symlinks+0xb4/0x12c
device_add+0x1e0/0x48c
device_register+0x20/0x34
extcon_dev_register+0x3b8/0x5c4
Fixes: 7bba9e81a6 ("extcon: Use unique number for the extcon device ID")
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Michael Wu <michael@allwinnertech.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Link: https://lore.kernel.org/lkml/20251024024946.16618-1-michael@allwinnertech.com/
8857f2495a