Dear Bio
I add this parameter in the mmcargs and the value of /proc/cmdline is
console=ttymxc0,115200 earlycon=ec_imx6q,0x30860000,115200 root=/dev/mmcblk1p2 rootwait rw video=HDMI-A-1:1280x720-32@60
But it`s still no sound out from HDMI. how to switch sound from lineout to HDMI. Without the param "video=HDMI-A-1" has images out from the HDMI when played the video.