drm/vc4: Fix support for interlaced modes on HDMI.

We really do need to be using the halved V fields.  I had been
confused by the code I was using as a reference because it stored
halved vsync fields but not halved vdisplay, so it looked like I only
needed to divide vdisplay by 2.

This reverts part of Mario's timestamping fixes that prevented
CRTC_HALVE_V from applying, and instead adjusts the timestamping code
to not use the crtc field in that case.

Fixes locking of 1920x1080x60i on my Dell 2408WFP.  There are black
bars on the top and bottom, but I suspect that might be an
under/overscan flags problem as opposed to video timings.

Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 12 insertions, 33 deletions

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index fe1c4e35e681..d94108ca961d 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -211,35 +211,10 @@ static int vc4_hdmi_connector_get_modes(struct drm_connector *connector)
 	return ret;
 }
 
-/*
- * drm_helper_probe_single_connector_modes() applies drm_mode_set_crtcinfo to
- * all modes with flag CRTC_INTERLACE_HALVE_V. We don't want this, as it
- * screws up vblank timestamping for interlaced modes, so fix it up.
- */
-static int vc4_hdmi_connector_probe_modes(struct drm_connector *connector,
-					  uint32_t maxX, uint32_t maxY)
-{
-	struct drm_display_mode *mode;
-	int count;
-
-	count = drm_helper_probe_single_connector_modes(connector, maxX, maxY);
-	if (count == 0)
-		return 0;
-
-	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed adapted modes :\n",
-		      connector->base.id, connector->name);
-	list_for_each_entry(mode, &connector->modes, head) {
-		drm_mode_set_crtcinfo(mode, 0);
-		drm_mode_debug_printmodeline(mode);
-	}
-
-	return count;
-}
-
 static const struct drm_connector_funcs vc4_hdmi_connector_funcs = {
 	.dpms = drm_atomic_helper_connector_dpms,
 	.detect = vc4_hdmi_connector_detect,
-	.fill_modes = vc4_hdmi_connector_probe_modes,
+	.fill_modes = drm_helper_probe_single_connector_modes,
 	.destroy = vc4_hdmi_connector_destroy,
 	.reset = drm_atomic_helper_connector_reset,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
@@ -307,16 +282,20 @@ static void vc4_hdmi_encoder_mode_set(struct drm_encoder *encoder,
 	bool debug_dump_regs = false;
 	bool hsync_pos = mode->flags & DRM_MODE_FLAG_PHSYNC;
 	bool vsync_pos = mode->flags & DRM_MODE_FLAG_PVSYNC;
-	u32 vactive = (mode->vdisplay >>
-		       ((mode->flags & DRM_MODE_FLAG_INTERLACE) ? 1 : 0));
-	u32 verta = (VC4_SET_FIELD(mode->vsync_end - mode->vsync_start,
+	bool interlaced = mode->flags & DRM_MODE_FLAG_INTERLACE;
+	u32 verta = (VC4_SET_FIELD(mode->crtc_vsync_end - mode->crtc_vsync_start,
 				   VC4_HDMI_VERTA_VSP) |
-		     VC4_SET_FIELD(mode->vsync_start - mode->vdisplay,
+		     VC4_SET_FIELD(mode->crtc_vsync_start - mode->crtc_vdisplay,
 				   VC4_HDMI_VERTA_VFP) |
-		     VC4_SET_FIELD(vactive, VC4_HDMI_VERTA_VAL));
+		     VC4_SET_FIELD(mode->crtc_vdisplay, VC4_HDMI_VERTA_VAL));
 	u32 vertb = (VC4_SET_FIELD(0, VC4_HDMI_VERTB_VSPO) |
-		     VC4_SET_FIELD(mode->vtotal - mode->vsync_end,
+		     VC4_SET_FIELD(mode->crtc_vtotal - mode->crtc_vsync_end,
 				   VC4_HDMI_VERTB_VBP));
+	u32 vertb_even = (VC4_SET_FIELD(0, VC4_HDMI_VERTB_VSPO) |
+			  VC4_SET_FIELD(mode->crtc_vtotal -
+					mode->crtc_vsync_end -
+					interlaced,
+					VC4_HDMI_VERTB_VBP));
 	u32 csc_ctl;
 
 	if (debug_dump_regs) {
@@ -349,7 +328,7 @@ static void vc4_hdmi_encoder_mode_set(struct drm_encoder *encoder,
 	HDMI_WRITE(VC4_HDMI_VERTA0, verta);
 	HDMI_WRITE(VC4_HDMI_VERTA1, verta);
 
-	HDMI_WRITE(VC4_HDMI_VERTB0, vertb);
+	HDMI_WRITE(VC4_HDMI_VERTB0, vertb_even);
 	HDMI_WRITE(VC4_HDMI_VERTB1, vertb);
 
 	HD_WRITE(VC4_HD_VID_CTL,