[RFC PATCH 06/11] drm/i915/psr: Add mechanism to notify PSR of pipe enable/disable

["Jouni Högander" <jouni.hogander@intel.com>]

We need to apply/remove workaround for underrun on idle PSR HW issue
(Wa_16025596647) when new pipe is enabled or pipe is getting disabled. This
patch implements mechanism to notify PSR about pipe enable/disable and
applies/removes the workaround using this notification.

Bspec: 74151

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
---
 drivers/gpu/drm/i915/display/intel_psr.c | 106 +++++++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_psr.h |   2 +
 2 files changed, 108 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index a3946eef44f0..4b62d5832cbf 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -26,6 +26,7 @@
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_damage_helper.h>
 #include <drm/drm_debugfs.h>
+#include <drm/drm_vblank.h>
 
 #include "i915_drv.h"
 #include "i915_reg.h"
@@ -3664,6 +3665,111 @@ void intel_psr_unlock(const struct intel_crtc_state *crtc_state)
 	}
 }
 
+/* Wa_16025596647 */
+static void psr1_apply_underrun_on_idle_wa_locked(struct intel_dp *intel_dp,
+						  bool dc5_dc6_blocked)
+{
+	struct intel_display *display = to_intel_display(intel_dp);
+	u32 val;
+
+	if (dc5_dc6_blocked)
+		val = DMC_EVT_CTL_ENABLE | DMC_EVT_CTL_RECURRING |
+			REG_FIELD_PREP(DMC_EVT_CTL_TYPE_MASK,
+				       DMC_EVT_CTL_TYPE_EDGE_0_1) |
+			REG_FIELD_PREP(DMC_EVT_CTL_EVENT_ID_MASK,
+				       DMC_EVT_CTL_EVENT_ID_VBLANK_A);
+	else
+		val = REG_FIELD_PREP(DMC_EVT_CTL_EVENT_ID_MASK,
+				     DMC_EVT_CTL_EVENT_ID_FALSE) |
+			REG_FIELD_PREP(DMC_EVT_CTL_TYPE_MASK,
+				       DMC_EVT_CTL_TYPE_EDGE_0_1);
+
+	intel_de_write(display, MTL_PIPEDMC_EVT_CTL_4(intel_dp->psr.pipe),
+		       val);
+}
+
+/* Wa_16025596647 */
+static bool is_dc5_dc6_blocked(struct intel_dp *intel_dp)
+{
+	struct intel_display *display = to_intel_display(intel_dp);
+	u32 current_dc_state = intel_display_power_get_current_dc_state(display);
+	struct drm_vblank_crtc *vblank = &display->drm->vblank[intel_dp->psr.pipe];
+
+	return (current_dc_state != DC_STATE_EN_UPTO_DC5 &&
+		current_dc_state != DC_STATE_EN_UPTO_DC6) ||
+		intel_dp->psr.active_non_psr_pipes ||
+		READ_ONCE(vblank->enabled);
+}
+
+/* Wa_16025596647 */
+static void intel_psr_apply_underrun_on_idle_wa_locked(struct intel_dp *intel_dp)
+{
+	bool dc5_dc6_blocked;
+
+	if (!intel_dp->psr.active)
+		return;
+
+	dc5_dc6_blocked = is_dc5_dc6_blocked(intel_dp);
+
+	if (intel_dp->psr.sel_update_enabled)
+		psr2_program_idle_frames(intel_dp, dc5_dc6_blocked ? 0 :
+					 psr_compute_idle_frames(intel_dp));
+	else
+		psr1_apply_underrun_on_idle_wa_locked(intel_dp, dc5_dc6_blocked);
+}
+
+/**
+ * intel_psr_notify_pipe_change - Notify PSR about enable/disable of a pipe
+ * @state: intel atomic state
+ * @crtc: intel crtc
+ * @enable: enable/disable
+ *
+ * This is targeted for underrun on idle PSR HW bug (Wa_16025596647) to apply
+ * remove the workaround when pipe is getting enabled/disabled
+ */
+void intel_psr_notify_pipe_change(struct intel_atomic_state *state,
+				  struct intel_crtc *crtc, bool enable)
+{
+	struct intel_display *display = to_intel_display(state);
+	struct intel_encoder *encoder;
+
+	if (DISPLAY_VER(display) != 20 &&
+	    !IS_DISPLAY_VERx100_STEP(display, 3000, STEP_A0, STEP_B0))
+		return;
+
+	for_each_intel_encoder_with_psr(display->drm, encoder) {
+		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
+		u8 active_non_psr_pipes;
+
+		mutex_lock(&intel_dp->psr.lock);
+
+		if (!intel_dp->psr.enabled || intel_dp->psr.panel_replay_enabled)
+			goto unlock;
+
+		active_non_psr_pipes = intel_dp->psr.active_non_psr_pipes;
+
+		if (enable)
+			active_non_psr_pipes |= BIT(crtc->pipe);
+		else
+			active_non_psr_pipes &= ~BIT(crtc->pipe);
+
+		if (active_non_psr_pipes == intel_dp->psr.active_non_psr_pipes)
+			goto unlock;
+
+		if ((enable && intel_dp->psr.active_non_psr_pipes) ||
+		    (!enable && !intel_dp->psr.active_non_psr_pipes)) {
+			intel_dp->psr.active_non_psr_pipes = active_non_psr_pipes;
+			goto unlock;
+		}
+
+		intel_dp->psr.active_non_psr_pipes = active_non_psr_pipes;
+
+		intel_psr_apply_underrun_on_idle_wa_locked(intel_dp);
+unlock:
+		mutex_unlock(&intel_dp->psr.lock);
+	}
+}
+
 static void
 psr_source_status(struct intel_dp *intel_dp, struct seq_file *m)
 {
diff --git a/drivers/gpu/drm/i915/display/intel_psr.h b/drivers/gpu/drm/i915/display/intel_psr.h
index a43a374cff55..273e70a50915 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.h
+++ b/drivers/gpu/drm/i915/display/intel_psr.h
@@ -60,6 +60,8 @@ void intel_psr2_program_trans_man_trk_ctl(struct intel_dsb *dsb,
 void intel_psr_pause(struct intel_dp *intel_dp);
 void intel_psr_resume(struct intel_dp *intel_dp);
 bool intel_psr_needs_block_dc_vblank(const struct intel_crtc_state *crtc_state);
+void intel_psr_notify_pipe_change(struct intel_atomic_state *state,
+				  struct intel_crtc *crtc, bool enable);
 bool intel_psr_link_ok(struct intel_dp *intel_dp);
 
 void intel_psr_lock(const struct intel_crtc_state *crtc_state);
-- 
2.43.0