aboutsummaryrefslogtreecommitdiff
path: root/drivers/gpu/drm
diff options
context:
space:
mode:
authorMario Kleiner <mario.kleiner@tuebingen.mpg.de>2011-02-21 05:42:02 +0100
committerDave Airlie <airlied@redhat.com>2011-02-23 10:08:49 +1000
commit9be6f8a978bdcbab46474a125aa4212516b71fe7 (patch)
tree060d33b9eef457ad6f794804052a443c6f91347a /drivers/gpu/drm
parentbc21512835a72bc1eab7abd7d8a1bff0435591d7 (diff)
downloadlinux-2.6.38-lt-ux500-9be6f8a978bdcbab46474a125aa4212516b71fe7.tar.gz
drm/vblank: Enable precise vblank timestamps for interlaced and doublescan modes.
Testing showed the current code can already handle doublescan video modes just fine. A trivial tweak makes it work for interlaced scanout as well. Tested and shown to be precise on Radeon rv530, r600 and Intel 945-GME. Signed-off-by: Mario Kleiner <mario.kleiner@tuebingen.mpg.de> Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu/drm')
-rw-r--r--drivers/gpu/drm/drm_irq.c14
1 files changed, 6 insertions, 8 deletions
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 22f3bf5ecbd..53120a72a48 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -493,6 +493,12 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc)
/* Dot clock in Hz: */
dotclock = (u64) crtc->hwmode.clock * 1000;
+ /* Fields of interlaced scanout modes are only halve a frame duration.
+ * Double the dotclock to get halve the frame-/line-/pixelduration.
+ */
+ if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE)
+ dotclock *= 2;
+
/* Valid dotclock? */
if (dotclock > 0) {
/* Convert scanline length in pixels and video dot clock to
@@ -605,14 +611,6 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
return -EAGAIN;
}
- /* Don't know yet how to handle interlaced or
- * double scan modes. Just no-op for now.
- */
- if (mode->flags & (DRM_MODE_FLAG_INTERLACE | DRM_MODE_FLAG_DBLSCAN)) {
- DRM_DEBUG("crtc %d: Noop due to unsupported mode.\n", crtc);
- return -ENOTSUPP;
- }
-
/* Get current scanout position with system timestamp.
* Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
* if single query takes longer than max_error nanoseconds.