The USB Adapter might can support 1.2A but the USB typeA only can provide current no more than 500mA.
T: Bus=01 Lev=02 Prnt=02 Port=02 Cnt=01 Dev#= 5 Spd=480 MxCh= 0
D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=2c7c ProdID=0901 Rev= 3.18
S: Manufacturer=Android
S: Product=Android
C:* #Ifs= 9 Cfg#= 1 Atr=e0 MxPwr=400mA
Maybe no more than 400mA.