Well, just tried spidev_test
on OEM fimrware. same result
root@CR1000A:/mnt# ./spidev_test -D /dev/spidev32765.0 -p "\x04" -v
spi mode: 0x0
bits per word: 8
max speed: 500000 Hz (500 kHz)
TX | 04 __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ |.|
RX | 00 __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ |.|