The task systemd-udevd hung in nvdimm_bus_check_dimm_count on Intel AEP platform

Issue

• The task systemd-udevd hung in nvdimm_bus_check_dimm_count:

PID: 603    TASK: ffff971986e9af70  CPU: 1   COMMAND: "systemd-udevd"
 #0 [ffff97198327f898] __schedule at ffffffff8c9128d4
 #1 [ffff97198327f928] schedule at ffffffff8c912f49
 #2 [ffff97198327f938] async_synchronize_cookie_domain at ffffffff8c2c23a5
 #3 [ffff97198327f990] async_synchronize_full_domain at ffffffff8c2c2488
 #4 [ffff97198327f9a0] nd_synchronize at ffffffffc05f5175 [libnvdimm]
 #5 [ffff97198327f9b0] nvdimm_bus_check_dimm_count at ffffffffc05f7135 [libnvdimm]
 #6 [ffff97198327f9e0] acpi_nfit_register_dimms at ffffffffc01dc086 [nfit]
 #7 [ffff97198327fa70] acpi_nfit_init at ffffffffc01dddd2 [nfit]
 #8 [ffff97198327fba0] acpi_nfit_add at ffffffffc01de174 [nfit]
 #9 [ffff97198327fbf0] acpi_device_probe at ffffffff8c5d437f
#10 [ffff97198327fc18] driver_probe_device at ffffffff8c6733d5
#11 [ffff97198327fc48] __driver_attach at ffffffff8c6737d3
#12 [ffff97198327fc70] bus_for_each_dev at ffffffff8c670f75
#13 [ffff97198327fcb0] driver_attach at ffffffff8c672d4e
#14 [ffff97198327fcc0] bus_add_driver at ffffffff8c6727f0
#15 [ffff97198327fcf0] driver_register at ffffffff8c673e64
#16 [ffff97198327fd10] acpi_bus_register_driver at ffffffff8c5d47e2
#17 [ffff97198327fd20] init_module at ffffffffc00bd13d [nfit]
#18 [ffff97198327fd38] do_one_initcall at ffffffff8c20210a
#19 [ffff97198327fd68] load_module at ffffffff8c30f5ac
#20 [ffff97198327feb8] sys_init_module at ffffffff8c30fb05
#21 [ffff97198327ff50] system_call_fastpath at ffffffff8c91f7d5
    RIP: 00007f00c4a5217a  RSP: 00007ffef9e7b200  RFLAGS: 00010206
    RAX: 00000000000000af  RBX: 0000563e6e91aa40  RCX: 0000563e6e96d530
    RDX: 00007f00c536c039  RSI: 0000000000016ce9  RDI: 0000563e6e956840
    RBP: 00007f00c536c039   R8: 0000000000000000   R9: 0000563e6e91bc80
    R10: 0000563e6e91bc00  R11: 0000000000000202  R12: 0000563e6e956840
    R13: 0000563e6e8f83c0  R14: 0000000000020000  R15: 0000000000000000
    ORIG_RAX: 00000000000000af  CS: 0033  SS: 002b