drm/i915/cdclk: Drop tgl/dg2 cdclk bump hacks

No one ever figured out why bumping the cdclk helped
with whatever issue we were having at the time.
Remove the hacks and start from scratch so that we
can actually see if any problems still remain.
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240402155016.13733-4-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/display/intel_cdclk.c

@@ -2814,25 +2814,6 @@ int intel_crtc_compute_min_cdclk(const struct intel_crtc_state *crtc_state)
 	if (crtc_state->dsc.compression_enable)
 		min_cdclk = max(min_cdclk, intel_vdsc_min_cdclk(crtc_state));
 
-	/*
-	 * HACK. Currently for TGL/DG2 platforms we calculate
-	 * min_cdclk initially based on pixel_rate divided
-	 * by 2, accounting for also plane requirements,
-	 * however in some cases the lowest possible CDCLK
-	 * doesn't work and causing the underruns.
-	 * Explicitly stating here that this seems to be currently
-	 * rather a Hack, than final solution.
-	 */
-	if (IS_TIGERLAKE(dev_priv) || IS_DG2(dev_priv)) {
-		/*
-		 * Clamp to max_cdclk_freq in case pixel rate is higher,
-		 * in order not to break an 8K, but still leave W/A at place.
-		 */
-		min_cdclk = max_t(int, min_cdclk,
-				  min_t(int, crtc_state->pixel_rate,
-					dev_priv->display.cdclk.max_cdclk_freq));
-	}
-
 	return min_cdclk;
 }