***************
*** 644,659 ****
  	intel_clock_t clock;
  	int err = target;
  
- 	if (IS_I9XX(dev) && intel_pipe_has_type(crtc, INTEL_OUTPUT_LVDS) &&
- 	    (I915_READ(LVDS)) != 0) {
- 		/*
- 		 * For LVDS, if the panel is on, just rely on its current
- 		 * settings for dual-channel.  We haven't figured out how to
- 		 * reliably set up different single/dual channel state, if we
- 		 * even can.
- 		 */
- 		if ((I915_READ(LVDS) & LVDS_CLKB_POWER_MASK) ==
- 		    LVDS_CLKB_POWER_UP)
  			clock.p2 = limit->p2.p2_fast;
  		else
  			clock.p2 = limit->p2.p2_slow;
--- 643,651 ----
  	intel_clock_t clock;
  	int err = target;
  
+ 	if (intel_pipe_has_type(crtc, INTEL_OUTPUT_LVDS)) {
+ 
+ 		if (dev_priv->lvds_is_dual_channel)
  			clock.p2 = limit->p2.p2_fast;
  		else
  			clock.p2 = limit->p2.p2_slow;