[PATCH 4/5] drm/i915/display: Introduce new intel_psr_pause/resume function

[Gwan-gyeong Mun]

This introduces the following function that can enable and disable psr
without intel_crtc_state/drm_connector_state when intel_psr is already
enabled with current intel_crtc_state and drm_connector_state information.

- intel_psr_pause(): Pause current PSR. it deactivates current psr state.
- intel_psr_resume(): Resume paused PSR without intel_crtc_state and
                      drm_connector_state. It activates paused psr state.

v2: Add new _intel_psr_enable_locked() function for removing duplicated
    code. (Jose)
v3: Addressed review comments from Jose
    - Split this commit for adding of psr_interrupt_error_check() function.
    - Reorder a paused variable of intel_psr struct.
    - Move resetting of busy_frontbuffer_bits to _intel_psr_enable_locked().
    - Move printting drm_WARM_ON of psr.enabled to _intel_psr_enable_locked().
    - Remove the redundant check of psr paused or psr enabled.

Cc: José Roberto de Souza <jose.souza at intel.com>
Cc: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
---
 .../drm/i915/display/intel_display_types.h    |  1 +
 drivers/gpu/drm/i915/display/intel_psr.c      | 94 ++++++++++++++++---
 drivers/gpu/drm/i915/display/intel_psr.h      |  2 +
 3 files changed, 83 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 80113fe5f639..5983130a3f86 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1451,6 +1451,7 @@ struct intel_psr {
 	bool sink_support;
 	bool source_support;
 	bool enabled;
+	bool paused;
 	enum pipe pipe;
 	enum transcoder transcoder;
 	bool active;
diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 803052296a93..e63d260b5925 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -988,34 +988,24 @@ static bool psr_interrupt_error_check(struct intel_dp *intel_dp)
 	return true;
 }
 
-static void intel_psr_enable_locked(struct intel_dp *intel_dp,
-				    const struct intel_crtc_state *crtc_state,
-				    const struct drm_connector_state *conn_state)
+static void _intel_psr_enable_locked(struct intel_dp *intel_dp)
 {
 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
 	struct intel_encoder *encoder = &dig_port->base;
-	u32 val;
+	const struct intel_crtc_state *crtc_state =
+		to_intel_crtc_state(encoder->base.crtc->state);
 
 	drm_WARN_ON(&dev_priv->drm, intel_dp->psr.enabled);
 
-	intel_dp->psr.psr2_enabled = crtc_state->has_psr2;
 	intel_dp->psr.busy_frontbuffer_bits = 0;
-	intel_dp->psr.pipe = to_intel_crtc(crtc_state->uapi.crtc)->pipe;
-	intel_dp->psr.transcoder = crtc_state->cpu_transcoder;
-	/* DC5/DC6 requires at least 6 idle frames */
-	val = usecs_to_jiffies(intel_get_frame_time_us(crtc_state) * 6);
-	intel_dp->psr.dc3co_exit_delay = val;
-	intel_dp->psr.dc3co_exitline = crtc_state->dc3co_exitline;
-	intel_dp->psr.psr2_sel_fetch_enabled = crtc_state->enable_psr2_sel_fetch;
 
 	if (!psr_interrupt_error_check(intel_dp))
 		return;
 
 	drm_dbg_kms(&dev_priv->drm, "Enabling PSR%s\n",
 		    intel_dp->psr.psr2_enabled ? "2" : "1");
-	intel_dp_compute_psr_vsc_sdp(intel_dp, crtc_state, conn_state,
-				     &intel_dp->psr.vsc);
+
 	intel_write_dp_vsc_sdp(encoder, crtc_state, &intel_dp->psr.vsc);
 	intel_psr_enable_sink(intel_dp);
 	intel_psr_enable_source(intel_dp);
@@ -1024,6 +1014,28 @@ static void intel_psr_enable_locked(struct intel_dp *intel_dp,
 	intel_psr_activate(intel_dp);
 }
 
+static void intel_psr_enable_locked(struct intel_dp *intel_dp,
+				    const struct intel_crtc_state *crtc_state,
+				    const struct drm_connector_state *conn_state)
+{
+	u32 val;
+
+	intel_dp->psr.psr2_enabled = crtc_state->has_psr2;
+	intel_dp->psr.pipe = to_intel_crtc(crtc_state->uapi.crtc)->pipe;
+	intel_dp->psr.transcoder = crtc_state->cpu_transcoder;
+	/* DC5/DC6 requires at least 6 idle frames */
+	val = usecs_to_jiffies(intel_get_frame_time_us(crtc_state) * 6);
+	intel_dp->psr.dc3co_exit_delay = val;
+	intel_dp->psr.psr2_sel_fetch_enabled = crtc_state->enable_psr2_sel_fetch;
+	intel_dp->psr.dc3co_exitline = crtc_state->dc3co_exitline;
+	intel_dp->psr.paused = false;
+
+	intel_dp_compute_psr_vsc_sdp(intel_dp, crtc_state, conn_state,
+				     &intel_dp->psr.vsc);
+
+	_intel_psr_enable_locked(intel_dp);
+}
+
 /**
  * intel_psr_enable - Enable PSR
  * @intel_dp: Intel DP
@@ -1161,6 +1173,60 @@ void intel_psr_disable(struct intel_dp *intel_dp,
 	cancel_delayed_work_sync(&intel_dp->psr.dc3co_work);
 }
 
+/**
+ * intel_psr_pause - Pause PSR
+ * @intel_dp: Intel DP
+ *
+ * This function need to be called after enabling psr.
+ */
+void intel_psr_pause(struct intel_dp *intel_dp)
+{
+	struct intel_psr *psr = &intel_dp->psr;
+
+	if (!CAN_PSR(intel_dp))
+		return;
+
+	mutex_lock(&psr->lock);
+
+	if (!psr->enabled) {
+		mutex_unlock(&psr->lock);
+		return;
+	}
+
+	intel_psr_disable_locked(intel_dp);
+	psr->paused = true;
+
+	mutex_unlock(&psr->lock);
+
+	cancel_work_sync(&psr->work);
+	cancel_delayed_work_sync(&psr->dc3co_work);
+}
+
+/**
+ * intel_psr_resume - Resume PSR
+ * @intel_dp: Intel DP
+ *
+ * This function need to be called after pausing psr.
+ */
+void intel_psr_resume(struct intel_dp *intel_dp)
+{
+	struct intel_psr *psr = &intel_dp->psr;
+
+	if (!CAN_PSR(intel_dp))
+		return;
+
+	mutex_lock(&psr->lock);
+
+	if (!psr->paused)
+		goto unlock;
+
+	psr->paused = false;
+	_intel_psr_enable_locked(intel_dp);
+
+unlock:
+	mutex_unlock(&psr->lock);
+}
+
 static void psr_force_hw_tracking_exit(struct intel_dp *intel_dp)
 {
 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
diff --git a/drivers/gpu/drm/i915/display/intel_psr.h b/drivers/gpu/drm/i915/display/intel_psr.h
index 0491a49ffd50..8cc5e78fb1d2 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.h
+++ b/drivers/gpu/drm/i915/display/intel_psr.h
@@ -48,5 +48,7 @@ void intel_psr2_program_plane_sel_fetch(struct intel_plane *plane,
 					const struct intel_crtc_state *crtc_state,
 					const struct intel_plane_state *plane_state,
 					int color_plane);
+void intel_psr_pause(struct intel_dp *intel_dp);
+void intel_psr_resume(struct intel_dp *intel_dp);
 
 #endif /* __INTEL_PSR_H__ */
-- 
2.30.1