2 files changed, 144 insertions, 26 deletions

diff --git a/drivers/media/platform/vsp1/vsp1_drm.c b/drivers/media/platform/vsp1/vsp1_drm.c
index a9c5389..f82f83b 100644
--- a/drivers/media/platform/vsp1/vsp1_drm.c
+++ b/drivers/media/platform/vsp1/vsp1_drm.c
@@ -37,10 +37,15 @@ static void vsp1_du_pipeline_frame_end(struct vsp1_pipeline *pipe,
 				       unsigned int completion)
 {
 	struct vsp1_drm_pipeline *drm_pipe = to_vsp1_drm_pipeline(pipe);
+	bool complete = completion == VSP1_DL_FRAME_END_COMPLETED;
 
 	if (drm_pipe->du_complete)
-		drm_pipe->du_complete(drm_pipe->du_private,
-				      completion & VSP1_DL_FRAME_END_COMPLETED);
+		drm_pipe->du_complete(drm_pipe->du_private, complete);
+
+	if (completion & VSP1_DL_FRAME_END_INTERNAL) {
+		drm_pipe->force_bru_release = false;
+		wake_up(&drm_pipe->wait_queue);
+	}
 }
 
 /* -----------------------------------------------------------------------------
@@ -150,6 +155,10 @@ static int vsp1_du_pipeline_setup_rpf(struct vsp1_device *vsp1,
 }
 
 /* Setup the BRU source pad. */
+static int vsp1_du_pipeline_setup_inputs(struct vsp1_device *vsp1,
+					 struct vsp1_pipeline *pipe);
+static void vsp1_du_pipeline_configure(struct vsp1_pipeline *pipe);
+
 static int vsp1_du_pipeline_setup_bru(struct vsp1_device *vsp1,
 				      struct vsp1_pipeline *pipe)
 {
@@ -157,9 +166,94 @@ static int vsp1_du_pipeline_setup_bru(struct vsp1_device *vsp1,
 	struct v4l2_subdev_format format = {
 		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
 	};
+	struct vsp1_entity *bru;
 	int ret;
 
 	/*
+	 * Pick a BRU:
+	 * - If we need more than two inputs, use the main BRU.
+	 * - Otherwise, if we are not forced to release our BRU, keep it.
+	 * - Else, use any free BRU (randomly starting with the main BRU).
+	 */
+	if (pipe->num_inputs > 2)
+		bru = &vsp1->bru->entity;
+	else if (pipe->bru && !drm_pipe->force_bru_release)
+		bru = pipe->bru;
+	else if (!vsp1->bru->entity.pipe)
+		bru = &vsp1->bru->entity;
+	else
+		bru = &vsp1->brs->entity;
+
+	/* Switch BRU if needed. */
+	if (bru != pipe->bru) {
+		struct vsp1_entity *released_bru = NULL;
+
+		/* Release our BRU if we have one. */
+		if (pipe->bru) {
+			/*
+			 * The BRU might be acquired by the other pipeline in
+			 * the next step. We must thus remove it from the list
+			 * of entities for this pipeline. The other pipeline's
+			 * hardware configuration will reconfigure the BRU
+			 * routing.
+			 *
+			 * However, if the other pipeline doesn't acquire our
+			 * BRU, we need to keep it in the list, otherwise the
+			 * hardware configuration step won't disconnect it from
+			 * the pipeline. To solve this, store the released BRU
+			 * pointer to add it back to the list of entities later
+			 * if it isn't acquired by the other pipeline.
+			 */
+			released_bru = pipe->bru;
+
+			list_del(&pipe->bru->list_pipe);
+			pipe->bru->sink = NULL;
+			pipe->bru->pipe = NULL;
+			pipe->bru = NULL;
+		}
+
+		/*
+		 * If the BRU we need is in use, force the owner pipeline to
+		 * switch to the other BRU and wait until the switch completes.
+		 */
+		if (bru->pipe) {
+			struct vsp1_drm_pipeline *owner_pipe;
+
+			owner_pipe = to_vsp1_drm_pipeline(bru->pipe);
+			owner_pipe->force_bru_release = true;
+
+			vsp1_du_pipeline_setup_inputs(vsp1, &owner_pipe->pipe);
+			vsp1_du_pipeline_configure(&owner_pipe->pipe);
+
+			ret = wait_event_timeout(owner_pipe->wait_queue,
+						 !owner_pipe->force_bru_release,
+						 msecs_to_jiffies(500));
+			if (ret == 0)
+				dev_warn(vsp1->dev,
+					 "DRM pipeline %u reconfiguration timeout\n",
+					 owner_pipe->pipe.lif->index);
+		}
+
+		/*
+		 * If the BRU we have released previously hasn't been acquired
+		 * by the other pipeline, add it back to the entities list (with
+		 * the pipe pointer NULL) to let vsp1_du_pipeline_configure()
+		 * disconnect it from the hardware pipeline.
+		 */
+		if (released_bru && !released_bru->pipe)
+			list_add_tail(&released_bru->list_pipe,
+				      &pipe->entities);
+
+		/* Add the BRU to the pipeline. */
+		pipe->bru = bru;
+		pipe->bru->pipe = pipe;
+		pipe->bru->sink = &pipe->output->entity;
+		pipe->bru->sink_pad = 0;
+
+		list_add_tail(&pipe->bru->list_pipe, &pipe->entities);
+	}
+
+	/*
 	 * Configure the format on the BRU source and verify that it matches the
 	 * requested format. We don't set the media bus code as it is configured
 	 * on the BRU sink pad 0 and propagated inside the entity, not on the
@@ -198,7 +292,7 @@ static int vsp1_du_pipeline_setup_inputs(struct vsp1_device *vsp1,
 					 struct vsp1_pipeline *pipe)
 {
 	struct vsp1_rwpf *inputs[VSP1_MAX_RPF] = { NULL, };
-	struct vsp1_bru *bru = to_bru(&pipe->bru->subdev);
+	struct vsp1_bru *bru;
 	unsigned int i;
 	int ret;
 
@@ -209,15 +303,6 @@ static int vsp1_du_pipeline_setup_inputs(struct vsp1_device *vsp1,
 		struct vsp1_rwpf *rpf = vsp1->rpf[i];
 		unsigned int j;
 
-		/*
-		 * Make sure we don't accept more inputs than the hardware can
-		 * handle. This is a temporary fix to avoid display stall, we
-		 * need to instead allocate the BRU or BRS to display pipelines
-		 * dynamically based on the number of planes they each use.
-		 */
-		if (pipe->num_inputs >= pipe->bru->source_pad)
-			pipe->inputs[i] = NULL;
-
 		if (!pipe->inputs[i])
 			continue;
 
@@ -243,6 +328,8 @@ static int vsp1_du_pipeline_setup_inputs(struct vsp1_device *vsp1,
 		return ret;
 	}
 
+	bru = to_bru(&pipe->bru->subdev);
+
 	/* Setup the RPF input pipeline for every enabled input. */
 	for (i = 0; i < pipe->bru->source_pad; ++i) {
 		struct vsp1_rwpf *rpf = inputs[i];
@@ -339,6 +426,7 @@ static int vsp1_du_pipeline_setup_output(struct vsp1_device *vsp1,
 /* Configure all entities in the pipeline. */
 static void vsp1_du_pipeline_configure(struct vsp1_pipeline *pipe)
 {
+	struct vsp1_drm_pipeline *drm_pipe = to_vsp1_drm_pipeline(pipe);
 	struct vsp1_entity *entity;
 	struct vsp1_entity *next;
 	struct vsp1_dl_list *dl;
@@ -369,7 +457,7 @@ static void vsp1_du_pipeline_configure(struct vsp1_pipeline *pipe)
 		}
 	}
 
-	vsp1_dl_list_commit(dl, false);
+	vsp1_dl_list_commit(dl, drm_pipe->force_bru_release);
 }
 
 /* -----------------------------------------------------------------------------
@@ -414,7 +502,6 @@ int vsp1_du_setup_lif(struct device *dev, unsigned int pipe_index,
 	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
 	struct vsp1_drm_pipeline *drm_pipe;
 	struct vsp1_pipeline *pipe;
-	struct vsp1_bru *bru;
 	unsigned long flags;
 	unsigned int i;
 	int ret;
@@ -424,9 +511,14 @@ int vsp1_du_setup_lif(struct device *dev, unsigned int pipe_index,
 
 	drm_pipe = &vsp1->drm->pipe[pipe_index];
 	pipe = &drm_pipe->pipe;
-	bru = to_bru(&pipe->bru->subdev);
 
 	if (!cfg) {
+		struct vsp1_bru *bru;
+
+		mutex_lock(&vsp1->drm->lock);
+
+		bru = to_bru(&pipe->bru->subdev);
+
 		/*
 		 * NULL configuration means the CRTC is being disabled, stop
 		 * the pipeline and turn the light off.
@@ -456,6 +548,12 @@ int vsp1_du_setup_lif(struct device *dev, unsigned int pipe_index,
 		drm_pipe->du_complete = NULL;
 		pipe->num_inputs = 0;
 
+		list_del(&pipe->bru->list_pipe);
+		pipe->bru->pipe = NULL;
+		pipe->bru = NULL;
+
+		mutex_unlock(&vsp1->drm->lock);
+
 		vsp1_dlm_reset(pipe->output->dlm);
 		vsp1_device_put(vsp1);
 
@@ -470,19 +568,21 @@ int vsp1_du_setup_lif(struct device *dev, unsigned int pipe_index,
 	dev_dbg(vsp1->dev, "%s: configuring LIF%u with format %ux%u\n",
 		__func__, pipe_index, cfg->width, cfg->height);
 
+	mutex_lock(&vsp1->drm->lock);
+
 	/* Setup formats through the pipeline. */
 	ret = vsp1_du_pipeline_setup_inputs(vsp1, pipe);
 	if (ret < 0)
-		return ret;
+		goto unlock;
 
 	ret = vsp1_du_pipeline_setup_output(vsp1, pipe);
 	if (ret < 0)
-		return ret;
+		goto unlock;
 
 	/* Enable the VSP1. */
 	ret = vsp1_device_get(vsp1);
 	if (ret < 0)
-		return ret;
+		goto unlock;
 
 	/*
 	 * Register a callback to allow us to notify the DRM driver of frame
@@ -498,6 +598,12 @@ int vsp1_du_setup_lif(struct device *dev, unsigned int pipe_index,
 	/* Configure all entities in the pipeline. */
 	vsp1_du_pipeline_configure(pipe);
 
+unlock:
+	mutex_unlock(&vsp1->drm->lock);
+
+	if (ret < 0)
+		return ret;
+
 	/* Start the pipeline. */
 	spin_lock_irqsave(&pipe->irqlock, flags);
 	vsp1_pipeline_run(pipe);
@@ -516,6 +622,9 @@ EXPORT_SYMBOL_GPL(vsp1_du_setup_lif);
  */
 void vsp1_du_atomic_begin(struct device *dev, unsigned int pipe_index)
 {
+	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
+
+	mutex_lock(&vsp1->drm->lock);
 }
 EXPORT_SYMBOL_GPL(vsp1_du_atomic_begin);
 
@@ -629,6 +738,7 @@ void vsp1_du_atomic_flush(struct device *dev, unsigned int pipe_index)
 
 	vsp1_du_pipeline_setup_inputs(vsp1, pipe);
 	vsp1_du_pipeline_configure(pipe);
+	mutex_unlock(&vsp1->drm->lock);
 }
 EXPORT_SYMBOL_GPL(vsp1_du_atomic_flush);
 
@@ -667,28 +777,26 @@ int vsp1_drm_init(struct vsp1_device *vsp1)
 	if (!vsp1->drm)
 		return -ENOMEM;
 
+	mutex_init(&vsp1->drm->lock);
+
 	/* Create one DRM pipeline per LIF. */
 	for (i = 0; i < vsp1->info->lif_count; ++i) {
 		struct vsp1_drm_pipeline *drm_pipe = &vsp1->drm->pipe[i];
 		struct vsp1_pipeline *pipe = &drm_pipe->pipe;
 
+		init_waitqueue_head(&drm_pipe->wait_queue);
+
 		vsp1_pipeline_init(pipe);
 
 		pipe->frame_end = vsp1_du_pipeline_frame_end;
 
 		/*
-		 * The DRM pipeline is static, add entities manually. The first
-		 * pipeline uses the BRU and the second pipeline the BRS.
+		 * The output side of the DRM pipeline is static, add the
+		 * corresponding entities manually.
 		 */
-		pipe->bru = i == 0 ? &vsp1->bru->entity : &vsp1->brs->entity;
 		pipe->output = vsp1->wpf[i];
 		pipe->lif = &vsp1->lif[i]->entity;
 
-		pipe->bru->pipe = pipe;
-		pipe->bru->sink = &pipe->output->entity;
-		pipe->bru->sink_pad = 0;
-		list_add_tail(&pipe->bru->list_pipe, &pipe->entities);
-
 		pipe->output->entity.pipe = pipe;
 		pipe->output->entity.sink = pipe->lif;
 		pipe->output->entity.sink_pad = 0;
@@ -710,4 +818,5 @@ int vsp1_drm_init(struct vsp1_device *vsp1)
 
 void vsp1_drm_cleanup(struct vsp1_device *vsp1)
 {
+	mutex_destroy(&vsp1->drm->lock);
 }
diff --git a/drivers/media/platform/vsp1/vsp1_drm.h b/drivers/media/platform/vsp1/vsp1_drm.h
index c8dd75b..c84bc1c 100644
--- a/drivers/media/platform/vsp1/vsp1_drm.h
+++ b/drivers/media/platform/vsp1/vsp1_drm.h
@@ -13,7 +13,9 @@
 #ifndef __VSP1_DRM_H__
 #define __VSP1_DRM_H__
 
+#include <linux/mutex.h>
 #include <linux/videodev2.h>
+#include <linux/wait.h>
 
 #include "vsp1_pipe.h"
 
@@ -22,6 +24,8 @@
  * @pipe: the VSP1 pipeline used for display
  * @width: output display width
  * @height: output display height
+ * @force_bru_release: when set, release the BRU during the next reconfiguration
+ * @wait_queue: wait queue to wait for BRU release completion
  * @du_complete: frame completion callback for the DU driver (optional)
  * @du_private: data to be passed to the du_complete callback
  */
@@ -31,6 +35,9 @@ struct vsp1_drm_pipeline {
 	unsigned int width;
 	unsigned int height;
 
+	bool force_bru_release;
+	wait_queue_head_t wait_queue;
+
 	/* Frame synchronisation */
 	void (*du_complete)(void *, bool);
 	void *du_private;
@@ -39,11 +46,13 @@ struct vsp1_drm_pipeline {
 /**
  * vsp1_drm - State for the API exposed to the DRM driver
  * @pipe: the VSP1 DRM pipeline used for display
+ * @lock: protects the BRU and BRS allocation
  * @inputs: source crop rectangle, destination compose rectangle and z-order
  *	position for every input (indexed by RPF index)
  */
 struct vsp1_drm {
 	struct vsp1_drm_pipeline pipe[VSP1_MAX_LIF];
+	struct mutex lock;
 
 	struct {
 		struct v4l2_rect crop;