diff options
| -rw-r--r-- | drivers/gpu/drm/drm_vblank.c | 59 | ||||
| -rw-r--r-- | include/drm/drm_vblank.h | 2 |
2 files changed, 61 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index 913954765d9e..c781cb426bf1 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -1237,6 +1237,65 @@ void drm_crtc_vblank_on(struct drm_crtc *crtc) } EXPORT_SYMBOL(drm_crtc_vblank_on); +/** + * drm_vblank_restore - estimated vblanks using timestamps and update it. + * + * Power manamement features can cause frame counter resets between vblank + * disable and enable. Drivers can then use this function in their + * &drm_crtc_funcs.enable_vblank implementation to estimate the vblanks since + * the last &drm_crtc_funcs.disable_vblank. + * + * This function is the legacy version of drm_crtc_vblank_restore(). + */ +void drm_vblank_restore(struct drm_device *dev, unsigned int pipe) +{ + ktime_t t_vblank; + struct drm_vblank_crtc *vblank; + int framedur_ns; + u64 diff_ns; + u32 cur_vblank, diff = 1; + int count = DRM_TIMESTAMP_MAXRETRIES; + + if (WARN_ON(pipe >= dev->num_crtcs)) + return; + + assert_spin_locked(&dev->vbl_lock); + assert_spin_locked(&dev->vblank_time_lock); + + vblank = &dev->vblank[pipe]; + WARN_ONCE((drm_debug & DRM_UT_VBL) && !vblank->framedur_ns, + "Cannot compute missed vblanks without frame duration\n"); + framedur_ns = vblank->framedur_ns; + + do { + cur_vblank = __get_vblank_counter(dev, pipe); + drm_get_last_vbltimestamp(dev, pipe, &t_vblank, false); + } while (cur_vblank != __get_vblank_counter(dev, pipe) && --count > 0); + + diff_ns = ktime_to_ns(ktime_sub(t_vblank, vblank->time)); + if (framedur_ns) + diff = DIV_ROUND_CLOSEST_ULL(diff_ns, framedur_ns); + + + DRM_DEBUG_VBL("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); +} +EXPORT_SYMBOL(drm_vblank_restore); + +/** + * drm_crtc_vblank_restore - estimate vblanks using timestamps and update it. + * Power manamement features can cause frame counter resets between vblank + * disable and enable. Drivers can then use this function in their + * &drm_crtc_funcs.enable_vblank implementation to estimate the vblanks since + * the last &drm_crtc_funcs.disable_vblank. + */ +void drm_crtc_vblank_restore(struct drm_crtc *crtc) +{ + drm_vblank_restore(crtc->dev, drm_crtc_index(crtc)); +} +EXPORT_SYMBOL(drm_crtc_vblank_restore); + static void drm_legacy_vblank_pre_modeset(struct drm_device *dev, unsigned int pipe) { diff --git a/include/drm/drm_vblank.h b/include/drm/drm_vblank.h index a4c3b0a0a197..16d46e2a6854 100644 --- a/include/drm/drm_vblank.h +++ b/include/drm/drm_vblank.h @@ -180,6 +180,8 @@ void drm_crtc_vblank_off(struct drm_crtc *crtc); void drm_crtc_vblank_reset(struct drm_crtc *crtc); void drm_crtc_vblank_on(struct drm_crtc *crtc); u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc); +void drm_vblank_restore(struct drm_device *dev, unsigned int pipe); +void drm_crtc_vblank_restore(struct drm_crtc *crtc); bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, unsigned int pipe, int *max_error, |