PANEL_POWER_RESET
pp &= ~PANEL_POWER_RESET;
pp |= PANEL_POWER_RESET;
pp |= PANEL_POWER_RESET; /* restore panel reset bit */
pp &= ~(PANEL_POWER_ON | PANEL_POWER_RESET | EDP_FORCE_VDD |
pps->powerdown_on_reset = I915_READ(PP_CONTROL(0)) & PANEL_POWER_RESET;
val |= PANEL_POWER_RESET;