diff options
Diffstat (limited to 'drivers/gpu/drm/drm_vblank.c')
| -rw-r--r-- | drivers/gpu/drm/drm_vblank.c | 28 |
1 files changed, 12 insertions, 16 deletions
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index 893165eeddf3..3417e1ac7918 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -1470,20 +1470,7 @@ void drm_crtc_vblank_on(struct drm_crtc *crtc) } EXPORT_SYMBOL(drm_crtc_vblank_on); -/** - * drm_vblank_restore - estimate missed vblanks and update vblank count. - * @dev: DRM device - * @pipe: CRTC index - * - * Power manamement features can cause frame counter resets between vblank - * disable and enable. Drivers can use this function in their - * &drm_crtc_funcs.enable_vblank implementation to estimate missed vblanks since - * the last &drm_crtc_funcs.disable_vblank using timestamps and update the - * vblank counter. - * - * This function is the legacy version of drm_crtc_vblank_restore(). - */ -void drm_vblank_restore(struct drm_device *dev, unsigned int pipe) +static void drm_vblank_restore(struct drm_device *dev, unsigned int pipe) { ktime_t t_vblank; struct drm_vblank_crtc *vblank; @@ -1491,6 +1478,7 @@ void drm_vblank_restore(struct drm_device *dev, unsigned int pipe) u64 diff_ns; u32 cur_vblank, diff = 1; int count = DRM_TIMESTAMP_MAXRETRIES; + u32 max_vblank_count = drm_max_vblank_count(dev, pipe); if (drm_WARN_ON(dev, pipe >= dev->num_crtcs)) return; @@ -1517,9 +1505,8 @@ void drm_vblank_restore(struct drm_device *dev, unsigned int pipe) drm_dbg_vbl(dev, "missed %d vblanks in %lld ns, frame duration=%d ns, hw_diff=%d\n", diff, diff_ns, framedur_ns, cur_vblank - vblank->last); - store_vblank(dev, pipe, diff, t_vblank, cur_vblank); + vblank->last = (cur_vblank - diff) & max_vblank_count; } -EXPORT_SYMBOL(drm_vblank_restore); /** * drm_crtc_vblank_restore - estimate missed vblanks and update vblank count. @@ -1530,9 +1517,18 @@ EXPORT_SYMBOL(drm_vblank_restore); * &drm_crtc_funcs.enable_vblank implementation to estimate missed vblanks since * the last &drm_crtc_funcs.disable_vblank using timestamps and update the * vblank counter. + * + * Note that drivers must have race-free high-precision timestamping support, + * i.e. &drm_crtc_funcs.get_vblank_timestamp must be hooked up and + * &drm_driver.vblank_disable_immediate must be set to indicate the + * time-stamping functions are race-free against vblank hardware counter + * increments. */ void drm_crtc_vblank_restore(struct drm_crtc *crtc) { + WARN_ON_ONCE(!crtc->funcs->get_vblank_timestamp); + WARN_ON_ONCE(!crtc->dev->vblank_disable_immediate); + drm_vblank_restore(crtc->dev, drm_crtc_index(crtc)); } EXPORT_SYMBOL(drm_crtc_vblank_restore); |