[Intel-gfx] [PATCH 20/24] drm/i915: Disable LP1+ watermarks while changing the number of active pipes

ville.syrjala at linux.intel.com ville.syrjala at linux.intel.com
Fri Mar 7 17:32:27 CET 2014


From: Ville Syrjälä <ville.syrjala at linux.intel.com>

When we switch between one active pipe and multiple active pipes, the
display FIFO gets repartitioned. Disable the LP1+ waterwarks while that
is happening to make sure we don't get any glitches on other active
pipes while doing a modeset on another other pipe.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 45 +++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_drv.h     |  2 ++
 drivers/gpu/drm/i915/intel_pm.c      | 48 ++++++++++++++++++++++++++++++++----
 3 files changed, 90 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index ad36749..9c43751 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3642,6 +3642,27 @@ static struct intel_crtc *get_other_active_crtc(struct intel_crtc *crtc)
 	return other_active_crtc;
 }
 
+static void ilk_prepare_for_num_pipes_change(struct intel_crtc *crtc)
+{
+	struct drm_device *dev = crtc->base.dev;
+	struct intel_crtc *other_active_crtc = get_other_active_crtc(crtc);
+
+	/*
+	 * If we change between one pipe and multiple pipes,
+	 * make sure the other active pipe is prepared
+	 * for having its FIFO resized. We do that by making
+	 * sure the pipe isn't using LP1+ watermarks when
+	 * the second pipe gets enabled or disabled.
+	 */
+	if (!other_active_crtc)
+		return;
+
+	ilk_wm_synchronize(&other_active_crtc->base);
+
+	if (ilk_disable_lp_wm(dev))
+		intel_wait_for_vblank(dev, other_active_crtc->pipe);
+}
+
 static void ironlake_crtc_enable(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;
@@ -3657,6 +3678,9 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc)
 
 	intel_crtc->active = true;
 
+	/* Make sure other pipes are prepared for FIFO resizing */
+	ilk_prepare_for_num_pipes_change(intel_crtc);
+
 	intel_set_cpu_fifo_underrun_reporting(dev, pipe, true);
 	intel_set_pch_fifo_underrun_reporting(dev, pipe, true);
 
@@ -3745,6 +3769,9 @@ static void haswell_crtc_enable(struct drm_crtc *crtc)
 
 	intel_crtc->active = true;
 
+	/* Make sure other pipes are prepared for FIFO resizing */
+	ilk_prepare_for_num_pipes_change(intel_crtc);
+
 	intel_set_cpu_fifo_underrun_reporting(dev, pipe, true);
 	if (intel_crtc->config.has_pch_encoder)
 		intel_set_pch_fifo_underrun_reporting(dev, TRANSCODER_A, true);
@@ -3814,6 +3841,9 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc)
 
 	ilk_crtc_disable_planes(crtc);
 
+	/* Make sure other pipes are prepared for FIFO resizing */
+	ilk_prepare_for_num_pipes_change(intel_crtc);
+
 	for_each_encoder_on_crtc(dev, crtc, encoder)
 		encoder->disable(encoder);
 
@@ -3857,6 +3887,12 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc)
 
 	intel_crtc->active = false;
 
+	/*
+	 * Potentially let some other pipe use the
+	 * full FIFO, and re-enable LP1+ watermarks.
+	 */
+	ilk_wm_pipe_post_disable(crtc);
+
 	mutex_lock(&dev->struct_mutex);
 	intel_update_fbc(dev);
 	mutex_unlock(&dev->struct_mutex);
@@ -3876,6 +3912,9 @@ static void haswell_crtc_disable(struct drm_crtc *crtc)
 
 	ilk_crtc_disable_planes(crtc);
 
+	/* Make sure other pipes are prepared for FIFO resizing */
+	ilk_prepare_for_num_pipes_change(intel_crtc);
+
 	for_each_encoder_on_crtc(dev, crtc, encoder) {
 		intel_opregion_notify_encoder(encoder, false);
 		encoder->disable(encoder);
@@ -3903,6 +3942,12 @@ static void haswell_crtc_disable(struct drm_crtc *crtc)
 
 	intel_crtc->active = false;
 
+	/*
+	 * Potentially let some other pipe use the
+	 * full FIFO, and re-enable LP1+ watermarks.
+	 */
+	ilk_wm_pipe_post_disable(crtc);
+
 	mutex_lock(&dev->struct_mutex);
 	intel_update_fbc(dev);
 	mutex_unlock(&dev->struct_mutex);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 4d8f646..94e90ad 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -952,6 +952,8 @@ void intel_fini_runtime_pm(struct drm_i915_private *dev_priv);
 void ilk_wm_get_hw_state(struct drm_device *dev);
 void ilk_update_pipe_wm(struct drm_device *dev, enum pipe pipe);
 void ilk_wm_synchronize(struct drm_crtc *crtc);
+void ilk_wm_pipe_post_disable(struct drm_crtc *crtc);
+bool ilk_disable_lp_wm(struct drm_device *dev);
 
 
 /* intel_sdvo.c */
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index a76fa82..7230748 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2714,7 +2714,7 @@ static void ilk_write_wm_values(struct drm_i915_private *dev_priv,
 	}
 }
 
-static bool ilk_disable_lp_wm(struct drm_device *dev)
+bool ilk_disable_lp_wm(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	bool changed;
@@ -2822,16 +2822,17 @@ static void ilk_program_watermarks(struct drm_device *dev)
 	ilk_write_wm_values(dev_priv, &results);
 }
 
-static void ilk_update_watermarks(struct drm_device *dev)
+static void ilk_update_watermarks(struct drm_device *dev, bool force)
 {
 	bool changed;
 
 	changed = ilk_refresh_pending_watermarks(dev);
 
-	if (changed)
+	if (changed || force)
 		ilk_program_watermarks(dev);
 }
 
+/* Prepare the pipe to update the its watermarks on the next vblank */
 static void ilk_setup_pending_watermarks(struct intel_crtc *intel_crtc,
 					 const struct intel_pipe_wm *pipe_wm,
 					 u32 vbl_count)
@@ -2854,7 +2855,7 @@ static void ilk_setup_pending_watermarks(struct intel_crtc *intel_crtc,
 	spin_unlock_irq(&intel_crtc->wm.lock);
 
 	/* try to update immediately */
-	ilk_update_watermarks(dev);
+	ilk_update_watermarks(dev, false);
 
 	spin_lock_irq(&intel_crtc->wm.lock);
 
@@ -2949,7 +2950,7 @@ static void ilk_watermark_work(struct work_struct *work)
 
 	mutex_lock(&dev_priv->wm.mutex);
 
-	ilk_update_watermarks(dev_priv->dev);
+	ilk_update_watermarks(dev_priv->dev, false);
 
 	mutex_unlock(&dev_priv->wm.mutex);
 }
@@ -3011,6 +3012,43 @@ void ilk_wm_synchronize(struct drm_crtc *crtc)
 	mutex_unlock(&dev_priv->wm.mutex);
 }
 
+void ilk_wm_pipe_post_disable(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	struct ilk_pipe_wm_parameters params = {};
+	struct intel_pipe_wm pipe_wm = {};
+
+	WARN(intel_crtc->active, "pipe %c should be disabled\n",
+	     pipe_name(intel_crtc->pipe));
+
+	ilk_compute_wm_parameters(crtc, &params);
+
+	intel_compute_pipe_wm(crtc, &params, &pipe_wm);
+
+	mutex_lock(&dev_priv->wm.mutex);
+
+	spin_lock_irq(&intel_crtc->wm.lock);
+
+	WARN(intel_crtc->wm.dirty, "pipe %c disabled with dirty watermarks\n",
+	     pipe_name(intel_crtc->pipe));
+
+	/* clean up if something is left behind */
+	ilk_wm_cancel(intel_crtc);
+
+	spin_unlock_irq(&intel_crtc->wm.lock);
+
+	intel_crtc->wm.active = pipe_wm;
+
+	/* pending update (if any) got cancelled */
+	intel_crtc->wm.pending = intel_crtc->wm.active;
+
+	ilk_update_watermarks(dev, true);
+
+	mutex_unlock(&dev_priv->wm.mutex);
+}
+
 static int ilk_update_primary_wm(struct drm_crtc *crtc,
 				 struct intel_crtc_wm_config *config)
 {
-- 
1.8.3.2




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