drm/i915: tweak language in fastset pipe config compare logging

The "fastset mismatch" debug logging has been slightly confusing,
leading people to believe some error happened. Change it to the more
informative "fastset requirement not met", and add a final message about
this leading to full modeset.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230516094406.2675307-1-jani.nikula@intel.com

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

@@ -4865,7 +4865,7 @@ pipe_config_infoframe_mismatch(struct drm_i915_private *dev_priv,
 			return;
 
 		drm_dbg_kms(&dev_priv->drm,
-			    "fastset mismatch in %s infoframe\n", name);
+			    "fastset requirement not met in %s infoframe\n", name);
 		drm_dbg_kms(&dev_priv->drm, "expected:\n");
 		hdmi_infoframe_log(KERN_DEBUG, dev_priv->drm.dev, a);
 		drm_dbg_kms(&dev_priv->drm, "found:\n");
@@ -4890,7 +4890,7 @@ pipe_config_dp_vsc_sdp_mismatch(struct drm_i915_private *dev_priv,
 			return;
 
 		drm_dbg_kms(&dev_priv->drm,
-			    "fastset mismatch in %s dp sdp\n", name);
+			    "fastset requirement not met in %s dp sdp\n", name);
 		drm_dbg_kms(&dev_priv->drm, "expected:\n");
 		drm_dp_vsc_sdp_log(KERN_DEBUG, dev_priv->drm.dev, a);
 		drm_dbg_kms(&dev_priv->drm, "found:\n");
@@ -4931,7 +4931,7 @@ pipe_config_buffer_mismatch(struct drm_i915_private *dev_priv,
 		len = memcmp_diff_len(a, b, len);
 
 		drm_dbg_kms(&dev_priv->drm,
-			    "fastset mismatch in %s buffer\n", name);
+			    "fastset requirement not met in %s buffer\n", name);
 		print_hex_dump(KERN_DEBUG, "expected: ", DUMP_PREFIX_NONE,
 			       16, 0, a, len, false);
 		print_hex_dump(KERN_DEBUG, "found: ", DUMP_PREFIX_NONE,
@@ -4962,7 +4962,7 @@ pipe_config_mismatch(bool fastset, const struct intel_crtc *crtc,
 
 	if (fastset)
 		drm_dbg_kms(&i915->drm,
-			    "[CRTC:%d:%s] fastset mismatch in %s %pV\n",
+			    "[CRTC:%d:%s] fastset requirement not met in %s %pV\n",
 			    crtc->base.base.id, crtc->base.name, name, &vaf);
 	else
 		drm_err(&i915->drm, "[CRTC:%d:%s] mismatch in %s %pV\n",
@@ -5550,8 +5550,13 @@ static int intel_modeset_checks(struct intel_atomic_state *state)
 static void intel_crtc_check_fastset(const struct intel_crtc_state *old_crtc_state,
 				     struct intel_crtc_state *new_crtc_state)
 {
-	if (!intel_pipe_config_compare(old_crtc_state, new_crtc_state, true))
+	struct drm_i915_private *i915 = to_i915(old_crtc_state->uapi.crtc->dev);
+
+	if (!intel_pipe_config_compare(old_crtc_state, new_crtc_state, true)) {
+		drm_dbg_kms(&i915->drm, "fastset requirement not met, forcing full modeset\n");
+
 		return;
+	}
 
 	new_crtc_state->uapi.mode_changed = false;
 	if (!intel_crtc_needs_modeset(new_crtc_state))