drm/vc4: Allow interlaced HDMI modes from FKMS.

Having checked the firmware handling for interlaced modes,
it appears to be possible to support interlaced modes on
HDMI without adverse side effects, so do so.

https://github.com/raspberrypi/linux/issues/3694

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

diff --git a/drivers/gpu/drm/vc4/vc4_firmware_kms.c b/drivers/gpu/drm/vc4/vc4_firmware_kms.c
index 25a1f06..ab794ee 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_firmware_kms.c
+++ b/drivers/gpu/drm/vc4/vc4_firmware_kms.c
@@ -936,6 +936,9 @@ static void vc4_crtc_mode_set_nofb(struct drm_crtc *crtc)
                break;
        }
 
+       if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+               mb.timings.flags |= TIMINGS_FLAGS_INTERLACE;
+
        mb.timings.video_id_code = frame.avi.video_code;
 
        if (!vc4_encoder->hdmi_monitor) {
@@ -1632,7 +1635,7 @@ vc4_fkms_connector_init(struct drm_device *dev, struct drm_encoder *encoder,
                                   DRM_MODE_CONNECTOR_HDMIA);
                drm_connector_helper_add(connector,
                                         &vc4_fkms_connector_helper_funcs);
-               connector->interlace_allowed = 0;
+               connector->interlace_allowed = 1;
        }
 
        ret = drm_mode_create_tv_margin_properties(dev);