Re: [PATCH] drm/i915: Restarting the Idleness DRRS in drrs_flush

Daniel Vetter
2015-06-15T15:44:19Z

On Mon, Jun 15, 2015 at 08:50:05PM +0530, Ramalingam C wrote:
> Corrected the documentation on the intel_edp_drrs_flush and
> intel_edp_drrs_invalidate.
>
> And accordingly edp_drrs_flush function is modified to restart the idleness
> detection after upclocking.
>
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

Thanks for testing and updating the comments. I've added a note to the
commit that the kerneldoc is from you and applied the patch.
-Daniel

> ---
> drivers/gpu/drm/i915/intel_dp.c | 30 ++++++++++++++++++++----------
> 1 file changed, 20 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index fb3d7f1..d5d5980 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -5455,13 +5455,12 @@ unlock:
> }
>
> /**
> - * intel_edp_drrs_invalidate - Invalidate DRRS
> + * intel_edp_drrs_invalidate - Disable Idleness DRRS
> * @dev: DRM device
> * @frontbuffer_bits: frontbuffer plane tracking bits
> *
> - * When there is a disturbance on screen (due to cursor movement/time
> - * update etc), DRRS needs to be invalidated, i.e. need to switch to
> - * high RR.
> + * This function gets called everytime rendering on the given planes start.
> + * Hence DRRS needs to be Upclocked, i.e. (LOW_RR -> HIGH_RR).
> *
> * Dirty frontbuffers relevant to DRRS are tracked in busy_frontbuffer_bits.
> */
> @@ -5486,6 +5485,7 @@ void intel_edp_drrs_invalidate(struct drm_device *dev,
> crtc = dp_to_dig_port(dev_priv->drrs.dp)->base.base.crtc;
> pipe = to_intel_crtc(crtc)->pipe;
>
> + /* invalidate means busy screen hence upclock */
> if (dev_priv->drrs.refresh_rate_type == DRRS_LOW_RR) {
> intel_dp_set_drrs_state(dev_priv->dev,
> dev_priv->drrs.dp->attached_connector->panel.
> @@ -5499,13 +5499,14 @@ void intel_edp_drrs_invalidate(struct drm_device *dev,
> }
>
> /**
> - * intel_edp_drrs_flush - Flush DRRS
> + * intel_edp_drrs_flush - Restart Idleness DRRS
> * @dev: DRM device
> * @frontbuffer_bits: frontbuffer plane tracking bits
> *
> - * When there is no movement on screen, DRRS work can be scheduled.
> - * This DRRS work is responsible for setting relevant registers after a
> - * timeout of 1 second.
> + * This function gets called every time rendering on the given planes has
> + * completed or flip on a crtc is completed. So DRRS should be upclocked
> + * (LOW_RR -> HIGH_RR). And also Idleness detection should be started again,
> + * if no other planes are dirty.
> *
> * Dirty frontbuffers relevant to DRRS are tracked in busy_frontbuffer_bits.
> */
> @@ -5531,8 +5532,17 @@ void intel_edp_drrs_flush(struct drm_device *dev,
> pipe = to_intel_crtc(crtc)->pipe;
> dev_priv->drrs.busy_frontbuffer_bits &= ~frontbuffer_bits;
>
> - if (dev_priv->drrs.refresh_rate_type != DRRS_LOW_RR &&
> - !dev_priv->drrs.busy_frontbuffer_bits)
> + /* flush means busy screen hence upclock */
> + if (dev_priv->drrs.refresh_rate_type == DRRS_LOW_RR)
> + intel_dp_set_drrs_state(dev_priv->dev,
> + dev_priv->drrs.dp->attached_connector->panel.
> + fixed_mode->vrefresh);
> +
> + /*
> + * flush also means no more activity hence schedule downclock, if all
> + * other fbs are quiescent too
> + */
> + if (!dev_priv->drrs.busy_frontbuffer_bits)
> schedule_delayed_work(&dev_priv->drrs.work,
> msecs_to_jiffies(1000));
> mutex_unlock(&dev_priv->drrs.mutex);
> --
> 1.7.9.5
>

--
Daniel Vetter
Software Engineer, Intel Corporation