drm: Stop using linedur_ns and pixeldur_ns for vblank timestamps
linedur_ns, and especially pixeldur_ns are becoming rather inaccurate
to be used for the vblank timestamp correction. With 4k@60 the pixel
duration is already below 2ns, so the amount of error due to the
truncation to nanoseconds is introducing quite a bit of error.
We can avoid such problems if we instead calculate the timestamp
delta_ns directly from the dislay timings, avoiding the use of
these intermediate truncated values.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
[danvet: Squash in fixup from Thierry Reding for amdgpu.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/radeon/radeon_pm.c b/drivers/gpu/drm/radeon/radeon_pm.c
index 05751f3..10f4c12 100644
--- a/drivers/gpu/drm/radeon/radeon_pm.c
+++ b/drivers/gpu/drm/radeon/radeon_pm.c
@@ -1733,7 +1733,9 @@
*/
for (crtc = 0; (crtc < rdev->num_crtc) && in_vbl; crtc++) {
if (rdev->pm.active_crtcs & (1 << crtc)) {
- vbl_status = radeon_get_crtc_scanoutpos(rdev->ddev, crtc, 0, &vpos, &hpos, NULL, NULL);
+ vbl_status = radeon_get_crtc_scanoutpos(rdev->ddev, crtc, 0,
+ &vpos, &hpos, NULL, NULL,
+ &rdev->mode_info.crtcs[crtc]->base.hwmode);
if ((vbl_status & DRM_SCANOUTPOS_VALID) &&
!(vbl_status & DRM_SCANOUTPOS_IN_VBLANK))
in_vbl = false;