G2D_BIT_ENGINE_BUSY
clear_bit(G2D_BIT_ENGINE_BUSY, &g2d->flags);
clear_bit(G2D_BIT_ENGINE_BUSY, &g2d->flags);
set_bit(G2D_BIT_ENGINE_BUSY, &g2d->flags);
if (test_bit(G2D_BIT_ENGINE_BUSY, &g2d->flags))
clear_bit(G2D_BIT_ENGINE_BUSY, &g2d->flags);