[PATCH 2/8] drm/i915: Handle interlaced modes in intel_set_transcoder_timings_lrr()

[Ville Syrjala]

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

I want to start using intel_set_transcoder_timings_lrr() also for
fixing up the vblank delay during boot. To that end make sure it
can cope with interlaced modes as well.

Note that we have soft-defeatured interlaced modes on tgl+ so
technically this is dead code, but if we ever have the need to
bring interlaced support back it seems better to handle this.

Cc: Paz Zcharya <pazz at chromium.org>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 5ba3b2d658e5..1260e394afc7 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -2923,6 +2923,12 @@ static void intel_set_transcoder_timings_lrr(const struct intel_crtc_state *crtc
 	crtc_vblank_start = adjusted_mode->crtc_vblank_start;
 	crtc_vblank_end = adjusted_mode->crtc_vblank_end;
 
+	if (adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE) {
+		/* the chip adds 2 halflines automatically */
+		crtc_vtotal -= 1;
+		crtc_vblank_end -= 1;
+	}
+
 	if (DISPLAY_VER(dev_priv) >= 13) {
 		/*
 		 * VBLANK_START not used by hw, just clear it
@@ -2931,8 +2937,6 @@ static void intel_set_transcoder_timings_lrr(const struct intel_crtc_state *crtc
 		crtc_vblank_start = 1;
 	}
 
-	drm_WARN_ON(&dev_priv->drm, adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE);
-
 	/*
 	 * The hardware actually ignores TRANS_VBLANK.VBLANK_END in DP mode.
 	 * But let's write it anyway to keep the state checker happy.
-- 
2.45.2