[Intel-gfx] [PATCH 08/11] drm/i915/display/vrr: Send VRR push to flip the frame

[Manasi Navare]

VRR achieves vblank stretching using the HW PUSH functionality.
So once the VRR is enabled during modeset then for each flip
request from userspace, in the atomic tail pipe_update_end()
we need to set the VRR push bit in HW for it to terminate
the vblank at configured flipline or anytime after flipline
or latest at the Vmax.

The HW clears the PUSH bit after the double buffer updates
are completed.

Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
---
 drivers/gpu/drm/i915/display/intel_sprite.c |  5 +++++
 drivers/gpu/drm/i915/display/intel_vrr.c    | 17 +++++++++++++++++
 drivers/gpu/drm/i915/display/intel_vrr.h    |  1 +
 3 files changed, 23 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c b/drivers/gpu/drm/i915/display/intel_sprite.c
index b6deeb338477..cb10fe462f06 100644
--- a/drivers/gpu/drm/i915/display/intel_sprite.c
+++ b/drivers/gpu/drm/i915/display/intel_sprite.c
@@ -49,6 +49,7 @@
 #include "intel_psr.h"
 #include "intel_dsi.h"
 #include "intel_sprite.h"
+#include "intel_vrr.h"
 
 int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode,
 			     int usecs)
@@ -217,6 +218,10 @@ void intel_pipe_update_end(struct intel_crtc_state *new_crtc_state)
 	    intel_crtc_has_type(new_crtc_state, INTEL_OUTPUT_DSI))
 		icl_dsi_frame_update(new_crtc_state);
 
+	/* Send VRR Push to terminate Vblank */
+	if (new_crtc_state->vrr.enable)
+		intel_vrr_send_push(new_crtc_state);
+
 	/* We're still in the vblank-evade critical section, this can't race.
 	 * Would be slightly nice to just grab the vblank count and arm the
 	 * event outside of the critical section - the spinlock might spin for a
diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
index 7f1353bac583..ec1ce88e869c 100644
--- a/drivers/gpu/drm/i915/display/intel_vrr.c
+++ b/drivers/gpu/drm/i915/display/intel_vrr.c
@@ -102,3 +102,20 @@ void intel_vrr_enable(struct intel_encoder *encoder,
 		trans_push);
 }
 
+void intel_vrr_send_push(const struct intel_crtc_state *crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	enum pipe pipe = crtc->pipe;
+	u32 trans_push;
+
+	trans_push = intel_de_read(dev_priv, TRANS_PUSH(pipe));
+	WARN_ON(!(trans_push & TRANS_PUSH_EN));
+
+	trans_push |= TRANS_PUSH_SEND;
+	intel_de_write(dev_priv, TRANS_PUSH(pipe), trans_push);
+
+	drm_dbg(&dev_priv->drm, "Sending VRR Push on Pipe (%c)\n",
+		pipe_name(pipe));
+}
+
diff --git a/drivers/gpu/drm/i915/display/intel_vrr.h b/drivers/gpu/drm/i915/display/intel_vrr.h
index 05d982d6fbae..a6b78e1676cb 100644
--- a/drivers/gpu/drm/i915/display/intel_vrr.h
+++ b/drivers/gpu/drm/i915/display/intel_vrr.h
@@ -19,5 +19,6 @@ void intel_vrr_compute_config(struct intel_dp *intel_dp,
 			      struct intel_crtc_state *crtc_state);
 void intel_vrr_enable(struct intel_encoder *encoder,
 		      const struct intel_crtc_state *crtc_state);
+void intel_vrr_send_push(const struct intel_crtc_state *crtc_state);
 
 #endif /* __INTEL_VRR_H__ */
-- 
2.19.1