drm/i915: Calculate vblank timestamping constants before enabling vblank.

This is required to properly initialize vblanks on the active crtc.
Without it drm_calc_vbltimestamp_from_scanoutpos can fail with
crtc 0: Noop due to uninitialized mode.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5254a3a..1b8a17c 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -15239,6 +15239,7 @@ static void intel_sanitize_crtc(struct intel_crtc *crtc)
        /* restore vblank interrupts to correct state */
        drm_crtc_vblank_reset(&crtc->base);
        if (crtc->active) {
+               drm_calc_timestamping_constants(&crtc->base, &crtc->base.hwmode);
                update_scanline_offset(crtc);
                drm_crtc_vblank_on(&crtc->base);
        }