drm/i915/display/fbc: Disable fbc by default on TGL

Fbc is causing random underruns in CI execution on TGL platforms.
Disabling the same while the problem is being debugged and analyzed.

v2: Moved the check below the module param check (Ville)

Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200716145857.6911-1-uma.shankar@intel.comSigned-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

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

@@ -1426,6 +1426,13 @@ static int intel_sanitize_fbc_option(struct drm_i915_private *dev_priv)
 	if (!HAS_FBC(dev_priv))
 		return 0;
 
+	/*
+	 * Fbc is causing random underruns in CI execution on TGL platforms.
+	 * Disabling the same while the problem is being debugged and analyzed.
+	 */
+	if (IS_TIGERLAKE(dev_priv))
+		return 0;
+
 	if (IS_BROADWELL(dev_priv) || INTEL_GEN(dev_priv) >= 9)
 		return 1;