for (i = 0; i < num_crtcs; i++)
init_waitqueue_head(&dev->vblank[i].queue);
- DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
+ DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
/* Driver specific high-precision vblank timestamping supported? */
if (dev->driver->get_vblank_timestamp)
/* 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.
+ /* Fields of interlaced scanout modes are only half a frame duration.
+ * Double the dotclock to get half the frame-/line-/pixelduration.
*/
if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE)
dotclock *= 2;
* code gets preempted or delayed for some reason.
*/
for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
- /* Get system timestamp before query. */
- stime = ktime_get();
-
- /* Get vertical and horizontal scanout pos. vpos, hpos. */
- vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos, &hpos);
+ /*
+ * Get vertical and horizontal scanout position vpos, hpos,
+ * and bounding timestamps stime, etime, pre/post query.
+ */
+ vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos,
+ &hpos, &stime, &etime);
- /* Get system timestamp after query. */
- etime = ktime_get();
+ /*
+ * Get correction for CLOCK_MONOTONIC -> CLOCK_REALTIME if
+ * CLOCK_REALTIME is requested.
+ */
if (!drm_timestamp_monotonic)
mono_time_offset = ktime_get_monotonic_offset();
return -EIO;
}
+ /* Compute uncertainty in timestamp of scanout position query. */
duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
/* Accept result with < max_error nsecs timing uncertainty. */