drm/i915: Call drm_calc_timestamping_constants() earlier

Update the pixel/line/frame duration information when we switch to the
new pipe config. This will keep the timestamping constants in better
sync with the real hardware state.

Reviewed-by: mario.kleiner.de@gmail.com
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

drivers/gpu/drm/i915/intel_display.c

@@ -9660,6 +9660,14 @@ static int __intel_set_mode(struct drm_crtc *crtc,
 		/* mode_set/enable/disable functions rely on a correct pipe
 		 * config. */
 		to_intel_crtc(crtc)->config = *pipe_config;
+
+		/*
+		 * Calculate and store various constants which
+		 * are later needed by vblank and swap-completion
+		 * timestamping. They are derived from true hwmode.
+		 */
+		drm_calc_timestamping_constants(crtc,
+						&pipe_config->adjusted_mode);
 	}
 
 	/* Only after disabling all output pipelines that will be changed can we
@@ -9683,15 +9691,6 @@ static int __intel_set_mode(struct drm_crtc *crtc,
 	for_each_intel_crtc_masked(dev, prepare_pipes, intel_crtc)
 		dev_priv->display.crtc_enable(&intel_crtc->base);
 
-	if (modeset_pipes) {
-		/* Calculate and store various constants which
-		 * are later needed by vblank and swap-completion
-		 * timestamping. They are derived from true hwmode.
-		 */
-		drm_calc_timestamping_constants(crtc,
-						&pipe_config->adjusted_mode);
-	}
-
 	/* FIXME: add subpixel order */
 done:
 	if (ret && crtc->enabled)