diff options
Diffstat (limited to 'drivers/gpu/drm/drm_irq.c')
| -rw-r--r-- | drivers/gpu/drm/drm_irq.c | 25 |
1 files changed, 11 insertions, 14 deletions
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index f9af048828ea..d80d95289e10 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -219,7 +219,7 @@ int drm_vblank_init(struct drm_device *dev, int num_crtcs) 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) @@ -586,24 +586,20 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc, * code gets preempted or delayed for some reason. */ for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) { - /* Disable preemption to make it very likely to - * succeed in the first iteration even on PREEMPT_RT kernel. + /* + * Get vertical and horizontal scanout position vpos, hpos, + * and bounding timestamps stime, etime, pre/post query. */ - preempt_disable(); + vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos, + &hpos, &stime, &etime); - /* 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 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(); - preempt_enable(); - /* Return as no-op if scanout query unsupported or failed. */ if (!(vbl_status & DRM_SCANOUTPOS_VALID)) { DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n", @@ -611,6 +607,7 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc, 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. */ |