[PATCH 04/11] drm/i915: Introduce intel_mode_vdisplay()

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

The DSB code will need to know the hardware's idea of vertical
active, as that is also what defines the start of undelayed
vblank. Introduce a helper that gives us that information,
in line with the other intel_mode_v*() functions.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_vblank.c | 10 ++++++++++
 drivers/gpu/drm/i915/display/intel_vblank.h |  1 +
 2 files changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_vblank.c b/drivers/gpu/drm/i915/display/intel_vblank.c
index e5db54b1c632..5b065e1cd4e4 100644
--- a/drivers/gpu/drm/i915/display/intel_vblank.c
+++ b/drivers/gpu/drm/i915/display/intel_vblank.c
@@ -557,6 +557,16 @@ void intel_crtc_update_active_timings(const struct intel_crtc_state *crtc_state,
 	spin_unlock_irqrestore(&i915->drm.vblank_time_lock, irqflags);
 }
 
+int intel_mode_vdisplay(const struct drm_display_mode *mode)
+{
+	int vdisplay = mode->crtc_vdisplay;
+
+	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+		vdisplay = DIV_ROUND_UP(vdisplay, 2);
+
+	return vdisplay;
+}
+
 int intel_mode_vblank_start(const struct drm_display_mode *mode)
 {
 	int vblank_start = mode->crtc_vblank_start;
diff --git a/drivers/gpu/drm/i915/display/intel_vblank.h b/drivers/gpu/drm/i915/display/intel_vblank.h
index b51ae2c1039e..7e526f6861e4 100644
--- a/drivers/gpu/drm/i915/display/intel_vblank.h
+++ b/drivers/gpu/drm/i915/display/intel_vblank.h
@@ -20,6 +20,7 @@ struct intel_vblank_evade_ctx {
 	bool need_vlv_dsi_wa;
 };
 
+int intel_mode_vdisplay(const struct drm_display_mode *mode);
 int intel_mode_vblank_start(const struct drm_display_mode *mode);
 int intel_mode_vblank_end(const struct drm_display_mode *mode);
 int intel_mode_vtotal(const struct drm_display_mode *mode);
-- 
2.44.2