1.使用的是DRM驱动
打印信息为：
[ 1.509936] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[ 1.516596] [drm] No driver support for vblank timestamp query.
[ 1.522869] [drm] Cannot find any crtc or sizes
[ 1.528044] [drm] Initialized tilcdc 1.0.0 20121205 for 4830e000.lcdc on minor 0
2.使用modetest命令
trying to open device 'tilcdc'...done
