[PATCH v6] drm/i915/panelreplay: Panel replay workaround with VRR

[Animesh Manna]

Panel Replay VSC SDP not getting sent when VRR is enabled
and W1 and W2 are 0. So Program Set Context Latency in
TRANS_SET_CONTEXT_LATENCY register to at least a value of 1.

HSD: 14015406119

v1: Initial version.
v2: Update timings stored in adjusted_mode struct. [Ville]
v3: Add WA in compute_config(). [Ville]
v4:
- Add DISPLAY_VER() check and improve code comment. [Rodrigo]
- Introduce centralized intel_crtc_vblank_delay(). [Ville]
v5: Move to crtc_compute_config(). [Ville]
v6: Restrict DISPLAY_VER till 14. [Mitul]

Signed-off-by: Animesh Manna <animesh.manna at intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c | 22 ++++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_display.h |  1 +
 2 files changed, 23 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index c608329dac42..96dd5938229b 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -2504,10 +2504,15 @@ static int intel_crtc_compute_pipe_mode(struct intel_crtc_state *crtc_state)
 static int intel_crtc_compute_config(struct intel_atomic_state *state,
 				     struct intel_crtc *crtc)
 {
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 	struct intel_crtc_state *crtc_state =
 		intel_atomic_get_new_crtc_state(state, crtc);
 	int ret;
 
+	/* wa_14015401596: display versions 13, 14 */
+	if (IS_DISPLAY_VER(dev_priv, 13, 14))
+		intel_crtc_vblank_delay(crtc_state);
+
 	ret = intel_dpll_crtc_compute_clock(state, crtc);
 	if (ret)
 		return ret;
@@ -3917,6 +3922,23 @@ bool intel_crtc_get_pipe_config(struct intel_crtc_state *crtc_state)
 	return true;
 }
 
+void intel_crtc_vblank_delay(struct intel_crtc_state *crtc_state)
+{
+	struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
+
+	/*
+	 * wa_14015401596 for display versions >= 13.
+	 * Program Set Context Latency in TRANS_SET_CONTEXT_LATENCY register
+	 * to at least a value of 1 when Panel Replay is enabled with VRR.
+	 * Value for TRANS_SET_CONTEXT_LATENCY is calculated by substracting
+	 * crtc_vdisplay from crtc_vblank_start, so incrementing crtc_vblank_start
+	 * by 1 if both are equal.
+	 */
+	if (crtc_state->vrr.enable && crtc_state->has_panel_replay &&
+	    adjusted_mode->crtc_vblank_start == adjusted_mode->crtc_vdisplay)
+		adjusted_mode->crtc_vblank_start += 1;
+}
+
 int intel_dotclock_calculate(int link_freq,
 			     const struct intel_link_m_n *m_n)
 {
diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
index 56d1c0e3e62c..d426dd9f7f87 100644
--- a/drivers/gpu/drm/i915/display/intel_display.h
+++ b/drivers/gpu/drm/i915/display/intel_display.h
@@ -428,6 +428,7 @@ bool intel_crtc_is_bigjoiner_master(const struct intel_crtc_state *crtc_state);
 u8 intel_crtc_bigjoiner_slave_pipes(const struct intel_crtc_state *crtc_state);
 struct intel_crtc *intel_master_crtc(const struct intel_crtc_state *crtc_state);
 bool intel_crtc_get_pipe_config(struct intel_crtc_state *crtc_state);
+void intel_crtc_vblank_delay(struct intel_crtc_state *crtc_state);
 bool intel_pipe_config_compare(const struct intel_crtc_state *current_config,
 			       const struct intel_crtc_state *pipe_config,
 			       bool fastset);
-- 
2.29.0