30d5ac5184
Avoid drm vblank on/off for virtual displays to allow drm framework to ignore the vblank requests. Vblanks are unnecessary for writeback as it is triggered based on the frame-updates and not on any defined interval. In addition, avoid vblank callback registration for concurrent writeback encoder. Change-Id: I205734e2e3076469dc7f775566cf5e104bac4082 Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>