I was under impression that snapshot capture is supported for 805 and newer. I'm using HTC M9 with the following CPU config:
Processor : AArch64 Processor rev 2 (aarch64)
processor : 0
processor : 1
processor : 2
processor : 3
processor : 4
processor : 5
processor : 6
processor : 7
min_vddcx : 500000
min_vddmx : 575000
Features : fp asimd evtstrm aes pmull sha1 sha2 crc32
CPU implementer : 0x41
CPU architecture: 8
CPU variant : 0x0
CPU part : 0xd03
CPU revision : 2
Hardware : Qualcomm Technologies, Inc MSM8994