drm/i915: Nuke lvds downclock support

With the new DRRS code it kinda sticks out, and we never managed to
get this to work well enough without causing issues. Time to wave
goodbye.

I've decided to keep the logic for programming the reduced clocks
intact, but everything else is gone. If anyone ever wants to resurrect
this we need to redo it all anyway on top of the frontbuffer tracking.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 198fc3c..2ff9eb0 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -122,42 +122,6 @@
 	drm_mode_set_name(panel_fixed_mode);
 }
 
-static bool
-lvds_dvo_timing_equal_size(const struct lvds_dvo_timing *a,
-			   const struct lvds_dvo_timing *b)
-{
-	if (a->hactive_hi != b->hactive_hi ||
-	    a->hactive_lo != b->hactive_lo)
-		return false;
-
-	if (a->hsync_off_hi != b->hsync_off_hi ||
-	    a->hsync_off_lo != b->hsync_off_lo)
-		return false;
-
-	if (a->hsync_pulse_width != b->hsync_pulse_width)
-		return false;
-
-	if (a->hblank_hi != b->hblank_hi ||
-	    a->hblank_lo != b->hblank_lo)
-		return false;
-
-	if (a->vactive_hi != b->vactive_hi ||
-	    a->vactive_lo != b->vactive_lo)
-		return false;
-
-	if (a->vsync_off != b->vsync_off)
-		return false;
-
-	if (a->vsync_pulse_width != b->vsync_pulse_width)
-		return false;
-
-	if (a->vblank_hi != b->vblank_hi ||
-	    a->vblank_lo != b->vblank_lo)
-		return false;
-
-	return true;
-}
-
 static const struct lvds_dvo_timing *
 get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *lvds_lfp_data,
 		    const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs,
@@ -213,7 +177,7 @@
 	const struct lvds_dvo_timing *panel_dvo_timing;
 	const struct lvds_fp_timing *fp_timing;
 	struct drm_display_mode *panel_fixed_mode;
-	int i, downclock, drrs_mode;
+	int drrs_mode;
 
 	lvds_options = find_section(bdb, BDB_LVDS_OPTIONS);
 	if (!lvds_options)
@@ -272,30 +236,6 @@
 	DRM_DEBUG_KMS("Found panel mode in BIOS VBT tables:\n");
 	drm_mode_debug_printmodeline(panel_fixed_mode);
 
-	/*
-	 * Iterate over the LVDS panel timing info to find the lowest clock
-	 * for the native resolution.
-	 */
-	downclock = panel_dvo_timing->clock;
-	for (i = 0; i < 16; i++) {
-		const struct lvds_dvo_timing *dvo_timing;
-
-		dvo_timing = get_lvds_dvo_timing(lvds_lfp_data,
-						 lvds_lfp_data_ptrs,
-						 i);
-		if (lvds_dvo_timing_equal_size(dvo_timing, panel_dvo_timing) &&
-		    dvo_timing->clock < downclock)
-			downclock = dvo_timing->clock;
-	}
-
-	if (downclock < panel_dvo_timing->clock && i915.lvds_downclock) {
-		dev_priv->lvds_downclock_avail = 1;
-		dev_priv->lvds_downclock = downclock * 10;
-		DRM_DEBUG_KMS("LVDS downclock is found in VBT. "
-			      "Normal Clock %dKHz, downclock %dKHz\n",
-			      panel_fixed_mode->clock, 10*downclock);
-	}
-
 	fp_timing = get_lvds_fp_timing(bdb, lvds_lfp_data,
 				       lvds_lfp_data_ptrs,
 				       lvds_options->panel_type);