[PATCH 2/2] drm/i915/psr: Use DC_OFF wake reference to block DC6 on vblank enable

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

We are observing following warnings:

*ERROR* power well DC_off state mismatch (refcount 0/enabled 1)

gen9_dc_off_power_well_enabled is concidering target state DC_STATE_DISABLE
as DC_OFF power well being enabled. Fix this by using wakeref for the
purpose.

Fixes: aa451abcffb5 ("drm/i915/display: Prevent DC6 while vblank is enabled for Panel Replay")
Cc: <stable@vger.kernel.org> # v6.13+
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
---
 .../drm/i915/display/intel_display_types.h    |  2 ++
 drivers/gpu/drm/i915/display/intel_psr.c      | 24 +++++++------------
 2 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 26e59110e743..e2861476b215 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1789,6 +1789,8 @@ struct intel_psr {
 	u8 active_non_psr_pipes;
 
 	const char *no_psr_reason;
+
+	struct ref_tracker *vblank_wakeref;
 };
 
 struct intel_dp {
diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 657b1614cd65..a8f02f928bd8 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -4141,14 +4141,20 @@ void intel_psr_notify_vblank_enable_disable(struct intel_display *display,
 					    bool enable)
 {
 	struct intel_encoder *encoder;
-	bool block_dc_states = false;
 
 	for_each_intel_encoder_with_psr(display->drm, encoder) {
 		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 
 		mutex_lock(&intel_dp->psr.lock);
-		if (CAN_PANEL_REPLAY(intel_dp))
-			block_dc_states = true;
+		if (CAN_PANEL_REPLAY(intel_dp)) {
+			if (enable)
+				intel_dp->psr.vblank_wakeref =
+					intel_display_power_get(display,
+								POWER_DOMAIN_DC_OFF);
+			else
+				intel_display_power_put(display, POWER_DOMAIN_DC_OFF,
+							intel_dp->psr.vblank_wakeref);
+		}
 
 		if (intel_dp->psr.enabled && !intel_dp->psr.panel_replay_enabled &&
 		    intel_dp->psr.pkg_c_latency_used)
@@ -4156,18 +4162,6 @@ void intel_psr_notify_vblank_enable_disable(struct intel_display *display,
 
 		mutex_unlock(&intel_dp->psr.lock);
 	}
-
-	/*
-	 * NOTE: intel_display_power_set_target_dc_state is used
-	 * only by PSR code for DC3CO handling. DC3CO target
-	 * state is currently disabled in * PSR code. If DC3CO
-	 * is taken into use we need take that into account here
-	 * as well.
-	 */
-	if (block_dc_states)
-		intel_display_power_set_target_dc_state(display, enable ?
-							DC_STATE_DISABLE :
-							DC_STATE_EN_UPTO_DC6);
 }
 
 static void
-- 
2.43.0