[300m] Unable to cold boot wth serial


Whenever I first plug in the USB-TTL serial and then power on the GLi AR300M, the boot process stops at:


[code]U-Boot 1.1.4-g87b46363-dirty (Jul 6 2016 - 08:09:50)

cus531 - Honey Bee 2.0DRAM:
Honey Bee 2.0
ath_ddr_initial_config(195): (16bit) ddr2 init
tap = 0x00000003
Tap (low, high) = (0x8, 0x25)
Tap values = (0x16, 0x16, 0x16, 0x16)
128 MB
Top of RAM usable for U-Boot at: 88000000
Reserving 242k for U-Boot at: 87fc0000
Reserving 192k for malloc() at: 87f90000
Reserving 44 Bytes for Board Info at: 87f8ffd4
Reserving 36 Bytes for Global Data at: 87f8ffb0
Reserving 128k for boot params() at: 87f6ffb0
Stack Pointer at: 87f6ff98

However if I connect USB-TTL to my computer after 300M, or if I just reboot the 300M via ‘reboot’ I see the full uboot starting logs, along with kernel and at the end I can login to the device. Any idea what’s wrong here?

Seems it is a problem of voltage or something related to hardware IO.
Does this happen every time?