Controller gets stuck when disabling advertising (no assert)

[zephyrbot]

Reported by Johan Hedberg:

Occasionally after long periods of continuous scanning and sending out Mesh advertising packets, the controller gets stuck when disabling advertising without emitting any assert.

HCI:

< HCI Command: LE Set Advertise Enable (0x08|0x000a) plen 1 [hci1] 3472.571335
Advertising: Disabled (0x00)

backtrace:

(gdb) bt
#0 __SEV () at /home/jh/src/zephyr/ext/hal/cmsis/Include/cmsis_gcc.h:406
#1 cpu_sleep ()
at /home/jh/src/zephyr/subsys/bluetooth/controller/hal/cpu.h:14
#2 0x0000414a in role_disable (
ticker_id_primary=ticker_id_primary@entry=5 '\005',
ticker_id_stop=ticker_id_stop@entry=3 '\003')
at /home/jh/src/zephyr/subsys/bluetooth/controller/ll_sw/ctrl.c:7048
#3 0x00008b1e in radio_adv_disable ()
at /home/jh/src/zephyr/subsys/bluetooth/controller/ll_sw/ctrl.c:7272
#4 0x00009b22 in ll_adv_enable (enable=)
at /home/jh/src/zephyr/subsys/bluetooth/controller/ll_sw/ll.c:441
#5 0x00001782 in le_set_adv_enable (
buf=0x20002cc8 <_net_buf_pool_cmd_tx_pool>,
evt=0x20002c7c <tx_thread_stack+660>)
at /home/jh/src/zephyr/subsys/bluetooth/controller/hci/hci.c:385
#6 controller_cmd_handle (evt=0x20002c7c <tx_thread_stack+660>,
cmd=0x20002cc8 <_net_buf_pool_cmd_tx_pool>, ocf=10 '\n')
at /home/jh/src/zephyr/subsys/bluetooth/controller/hci/hci.c:759
#7 hci_cmd_handle (cmd=cmd@entry=0x20002cc8 <_net_buf_pool_cmd_tx_pool>)
at /home/jh/src/zephyr/subsys/bluetooth/controller/hci/hci.c:900
#8 0x00001efe in cmd_handle (buf=0x20002cc8 <_net_buf_pool_cmd_tx_pool>)
at /home/jh/src/zephyr/subsys/bluetooth/controller/hci/hci_driver.c:147
#9 hci_driver_send (buf=0x20002cc8 <_net_buf_pool_cmd_tx_pool>)
---Type to continue, or q to quit---
/zephyr/subsys/bluetooth/controller/hci/hci_driver.c:176

(Imported from Jira ZEP-1941)