@@ -163,14 +163,6 @@ int vc4_crtc_get_scanoutpos(struct drm_device *dev, unsigned int crtc_id,
int vblank_lines;
int ret = 0;
- /*
- * XXX Doesn't work well in interlaced mode yet, partially due
- * to problems in vc4 kms or drm core interlaced mode handling,
- * so disable for now in interlaced mode.
- */
- if (mode->flags & DRM_MODE_FLAG_INTERLACE)
- return ret;
-
/* preempt_disable_rt() should go right here in PREEMPT_RT patchset. */
/* Get optional system timestamp before query. */
@@ -191,10 +183,15 @@ int vc4_crtc_get_scanoutpos(struct drm_device *dev, unsigned int crtc_id,
/* Vertical position of hvs composed scanline. */
*vpos = VC4_GET_FIELD(val, SCALER_DISPSTATX_LINE);
+ *hpos = 0;
+
+ if (mode->flags & DRM_MODE_FLAG_INTERLACE) {
+ *vpos /= 2;
- /* No hpos info available. */
- if (hpos)
- *hpos = 0;
+ /* Use hpos to correct for field offset in interlaced mode. */
+ if (VC4_GET_FIELD(val, SCALER_DISPSTATX_FRAME_COUNT) % 2)
+ *hpos += mode->crtc_htotal / 2;
+ }
/* This is the offset we need for translating hvs -> pv scanout pos. */
fifo_lines = vc4_crtc->cob_size / mode->crtc_hdisplay;
@@ -217,8 +214,6 @@ int vc4_crtc_get_scanoutpos(struct drm_device *dev, unsigned int crtc_id,
* position of the PV.
*/
*vpos -= fifo_lines + 1;
- if (mode->flags & DRM_MODE_FLAG_INTERLACE)
- *vpos /= 2;
ret |= DRM_SCANOUTPOS_ACCURATE;
return ret;
On top of the interlaced video mode fix and with some additional adjustments, this now works well. It has almost the same accuracy as on regular progressive scan modes. Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com> Cc: Eric Anholt <eric@anholt.net> --- drivers/gpu/drm/vc4/vc4_crtc.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-)