System reboot after executing the hciattach command

We try to connect uart1 of WP7607 to WiFi module on mangOH yellow(remove R802 R803 R807 R806 , and wire to UART1 of WP7607)

we’re used “hciattach” to configure BT core

hciattach /dev/ttyHS0 bcm43xx 3000000 flow -t 20

But the system reboots itself after executing this command
Because there is no any dmesg (I also tried to monitor from the debug console), I have no idea what is going on , does anyone know why it reboot after execute hciattach command?

image


system info:
Device: WP7607
IMEI: 359779080309046
IMEISV: E
FSN: V3001787360210
Firmware Version: SWI9X07Y_02.37.03.00 73df45 jenkins 2020/04/08 10:59:14
Bootloader Version: SWI9X07Y_02.37.03.00 73df45 jenkins 2020/04/08 10:59:14
MCU Version: 002.015
PRI Part Number (PN): 9908663
PRI Revision: 001.002

It seems fixed if I change the uart to linux console via ATcommand