------------[ cut here ]------------
sysfs group 'power' not found for kobject 'ttyHS0'
WARNING: CPU: 0 PID: 5 at fs/sysfs/group.c:278 sysfs_remove_group fs/sysfs/group.c:278 [inline]
WARNING: CPU: 0 PID: 5 at fs/sysfs/group.c:278 sysfs_remove_group+0x155/0x1b0 fs/sysfs/group.c:269
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xca/0x13e lib/dump_stack.c:113
 panic+0x2aa/0x6e1 kernel/panic.c:221
 __warn.cold+0x2f/0x33 kernel/panic.c:582
 report_bug+0x27b/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x12b/0x1e0 arch/x86/kernel/traps.c:272
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:291
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:sysfs_remove_group fs/sysfs/group.c:278 [inline]
RIP: 0010:sysfs_remove_group+0x155/0x1b0 fs/sysfs/group.c:269
Code: 48 89 d9 49 8b 14 24 48 b8 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 01 00 75 41 48 8b 33 48 c7 c7 e0 a0 d0 85 e8 20 f0 89 ff <0f> 0b eb 95 e8 a2 9a db ff e9 d2 fe ff ff 48 89 df e8 95 9a db ff
RSP: 0018:ffff8881da1df110 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffffffff85f2c9e0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8128c9cd RDI: ffffed103b43be14
RBP: 0000000000000000 R08: ffff8881da196000 R09: fffffbfff11ab3ae
R10: fffffbfff11ab3ad R11: ffffffff88d59d6f R12: ffff8881cf8cf000
R13: ffffffff85f2cf80 R14: ffff8881cf418000 R15: ffff8881cfd8e070
 dpm_sysfs_remove+0x97/0xb0 drivers/base/power/sysfs.c:741
 device_del+0x12a/0xb20 drivers/base/core.c:2353
 device_unregister drivers/base/core.c:2408 [inline]
 device_destroy+0x96/0xe0 drivers/base/core.c:2987
 tty_unregister_device+0x7e/0x1a0 drivers/tty/tty_io.c:3185
 hso_serial_tty_unregister drivers/net/usb/hso.c:2231 [inline]
 hso_create_bulk_serial_device drivers/net/usb/hso.c:2677 [inline]
 hso_probe.cold+0x6e/0x14c drivers/net/usb/hso.c:2943
 usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
 really_probe+0x281/0x6d0 drivers/base/dd.c:548
 driver_probe_device+0x104/0x210 drivers/base/dd.c:721
 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
 __device_attach+0x217/0x360 drivers/base/dd.c:894
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
 device_add+0xae6/0x16f0 drivers/base/core.c:2202
 usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
 usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
 really_probe+0x281/0x6d0 drivers/base/dd.c:548
 driver_probe_device+0x104/0x210 drivers/base/dd.c:721
 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
 __device_attach+0x217/0x360 drivers/base/dd.c:894
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
 device_add+0xae6/0x16f0 drivers/base/core.c:2202
 usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2537
 hub_port_connect drivers/usb/core/hub.c:5184 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5324 [inline]
 port_event drivers/usb/core/hub.c:5470 [inline]
 hub_event+0x1df8/0x3800 drivers/usb/core/hub.c:5552
 process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
 worker_thread+0x96/0xe20 kernel/workqueue.c:2415
 kthread+0x318/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..