1 files changed, 70 insertions, 136 deletions

diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c b/drivers/media/platform/rcar-vin/rcar-dma.c
index 23fdff7..4a40e6a 100644
--- a/drivers/media/platform/rcar-vin/rcar-dma.c
+++ b/drivers/media/platform/rcar-vin/rcar-dma.c
@@ -168,12 +168,8 @@ static int rvin_setup(struct rvin_dev *vin)
 		break;
 	case V4L2_FIELD_ALTERNATE:
 	case V4L2_FIELD_NONE:
-		if (vin->continuous) {
-			vnmc = VNMC_IM_ODD_EVEN;
-			progressive = true;
-		} else {
-			vnmc = VNMC_IM_ODD;
-		}
+		vnmc = VNMC_IM_ODD_EVEN;
+		progressive = true;
 		break;
 	default:
 		vnmc = VNMC_IM_ODD;
@@ -298,14 +294,6 @@ static bool rvin_capture_active(struct rvin_dev *vin)
 	return rvin_read(vin, VNMS_REG) & VNMS_CA;
 }
 
-static int rvin_get_active_slot(struct rvin_dev *vin, u32 vnms)
-{
-	if (vin->continuous)
-		return (vnms & VNMS_FBS_MASK) >> VNMS_FBS_SHIFT;
-
-	return 0;
-}
-
 static enum v4l2_field rvin_get_active_field(struct rvin_dev *vin, u32 vnms)
 {
 	if (vin->format.field == V4L2_FIELD_ALTERNATE) {
@@ -344,76 +332,47 @@ static void rvin_set_slot_addr(struct rvin_dev *vin, int slot, dma_addr_t addr)
 	rvin_write(vin, offset, VNMB_REG(slot));
 }
 
-/* Moves a buffer from the queue to the HW slots */
-static bool rvin_fill_hw_slot(struct rvin_dev *vin, int slot)
+/*
+ * Moves a buffer from the queue to the HW slot. If no buffer is
+ * available use the scratch buffer. The scratch buffer is never
+ * returned to userspace, its only function is to enable the capture
+ * loop to keep running.
+ */
+static void rvin_fill_hw_slot(struct rvin_dev *vin, int slot)
 {
 	struct rvin_buffer *buf;
 	struct vb2_v4l2_buffer *vbuf;
-	dma_addr_t phys_addr_top;
-
-	if (vin->queue_buf[slot] != NULL)
-		return true;
+	dma_addr_t phys_addr;
 
-	if (list_empty(&vin->buf_list))
-		return false;
+	/* A already populated slot shall never be overwritten. */
+	if (WARN_ON(vin->queue_buf[slot] != NULL))
+		return;
 
 	vin_dbg(vin, "Filling HW slot: %d\n", slot);
 
-	/* Keep track of buffer we give to HW */
-	buf = list_entry(vin->buf_list.next, struct rvin_buffer, list);
-	vbuf = &buf->vb;
-	list_del_init(to_buf_list(vbuf));
-	vin->queue_buf[slot] = vbuf;
-
-	/* Setup DMA */
-	phys_addr_top = vb2_dma_contig_plane_dma_addr(&vbuf->vb2_buf, 0);
-	rvin_set_slot_addr(vin, slot, phys_addr_top);
-
-	return true;
-}
-
-static bool rvin_fill_hw(struct rvin_dev *vin)
-{
-	int slot, limit;
-
-	limit = vin->continuous ? HW_BUFFER_NUM : 1;
-
-	for (slot = 0; slot < limit; slot++)
-		if (!rvin_fill_hw_slot(vin, slot))
-			return false;
-	return true;
-}
-
-static void rvin_capture_on(struct rvin_dev *vin)
-{
-	vin_dbg(vin, "Capture on in %s mode\n",
-		vin->continuous ? "continuous" : "single");
+	if (list_empty(&vin->buf_list)) {
+		vin->queue_buf[slot] = NULL;
+		phys_addr = vin->scratch_phys;
+	} else {
+		/* Keep track of buffer we give to HW */
+		buf = list_entry(vin->buf_list.next, struct rvin_buffer, list);
+		vbuf = &buf->vb;
+		list_del_init(to_buf_list(vbuf));
+		vin->queue_buf[slot] = vbuf;
+
+		/* Setup DMA */
+		phys_addr = vb2_dma_contig_plane_dma_addr(&vbuf->vb2_buf, 0);
+	}
 
-	if (vin->continuous)
-		/* Continuous Frame Capture Mode */
-		rvin_write(vin, VNFC_C_FRAME, VNFC_REG);
-	else
-		/* Single Frame Capture Mode */
-		rvin_write(vin, VNFC_S_FRAME, VNFC_REG);
+	rvin_set_slot_addr(vin, slot, phys_addr);
 }
 
 static int rvin_capture_start(struct rvin_dev *vin)
 {
-	struct rvin_buffer *buf, *node;
-	int bufs, ret;
-
-	/* Count number of free buffers */
-	bufs = 0;
-	list_for_each_entry_safe(buf, node, &vin->buf_list, list)
-		bufs++;
+	int slot, ret;
 
-	/* Continuous capture requires more buffers then there are HW slots */
-	vin->continuous = bufs > HW_BUFFER_NUM;
-
-	if (!rvin_fill_hw(vin)) {
-		vin_err(vin, "HW not ready to start, not enough buffers available\n");
-		return -EINVAL;
-	}
+	for (slot = 0; slot < HW_BUFFER_NUM; slot++)
+		rvin_fill_hw_slot(vin, slot);
 
 	rvin_crop_scale_comp(vin);
 
@@ -421,7 +380,10 @@ static int rvin_capture_start(struct rvin_dev *vin)
 	if (ret)
 		return ret;
 
-	rvin_capture_on(vin);
+	vin_dbg(vin, "Starting to capture\n");
+
+	/* Continuous Frame Capture Mode */
+	rvin_write(vin, VNFC_C_FRAME, VNFC_REG);
 
 	vin->state = RUNNING;
 
@@ -904,7 +866,7 @@ static irqreturn_t rvin_irq(int irq, void *data)
 	struct rvin_dev *vin = data;
 	u32 int_status, vnms;
 	int slot;
-	unsigned int i, sequence, handled = 0;
+	unsigned int handled = 0;
 	unsigned long flags;
 
 	spin_lock_irqsave(&vin->qlock, flags);
@@ -930,65 +892,25 @@ static irqreturn_t rvin_irq(int irq, void *data)
 
 	/* Prepare for capture and update state */
 	vnms = rvin_read(vin, VNMS_REG);
-	slot = rvin_get_active_slot(vin, vnms);
-	sequence = vin->sequence++;
-
-	vin_dbg(vin, "IRQ %02d: %d\tbuf0: %c buf1: %c buf2: %c\tmore: %d\n",
-		sequence, slot,
-		slot == 0 ? 'x' : vin->queue_buf[0] != NULL ? '1' : '0',
-		slot == 1 ? 'x' : vin->queue_buf[1] != NULL ? '1' : '0',
-		slot == 2 ? 'x' : vin->queue_buf[2] != NULL ? '1' : '0',
-		!list_empty(&vin->buf_list));
-
-	/* HW have written to a slot that is not prepared we are in trouble */
-	if (WARN_ON((vin->queue_buf[slot] == NULL)))
-		goto done;
+	slot = (vnms & VNMS_FBS_MASK) >> VNMS_FBS_SHIFT;
 
 	/* Capture frame */
-	vin->queue_buf[slot]->field = rvin_get_active_field(vin, vnms);
-	vin->queue_buf[slot]->sequence = sequence;
-	vin->queue_buf[slot]->vb2_buf.timestamp = ktime_get_ns();
-	vb2_buffer_done(&vin->queue_buf[slot]->vb2_buf, VB2_BUF_STATE_DONE);
-	vin->queue_buf[slot] = NULL;
-
-	/* Prepare for next frame */
-	if (!rvin_fill_hw(vin)) {
-
-		/*
-		 * Can't supply HW with new buffers fast enough. Halt
-		 * capture until more buffers are available.
-		 */
-		vin->state = STALLED;
-
-		/*
-		 * The continuous capturing requires an explicit stop
-		 * operation when there is no buffer to be set into
-		 * the VnMBm registers.
-		 */
-		if (vin->continuous) {
-			rvin_capture_stop(vin);
-			vin_dbg(vin, "IRQ %02d: hw not ready stop\n", sequence);
-
-			/* Maybe we can continue in single capture mode */
-			for (i = 0; i < HW_BUFFER_NUM; i++) {
-				if (vin->queue_buf[i]) {
-					list_add(to_buf_list(vin->queue_buf[i]),
-						 &vin->buf_list);
-					vin->queue_buf[i] = NULL;
-				}
-			}
-
-			if (!list_empty(&vin->buf_list))
-				rvin_capture_start(vin);
-		}
+	if (vin->queue_buf[slot]) {
+		vin->queue_buf[slot]->field = rvin_get_active_field(vin, vnms);
+		vin->queue_buf[slot]->sequence = vin->sequence;
+		vin->queue_buf[slot]->vb2_buf.timestamp = ktime_get_ns();
+		vb2_buffer_done(&vin->queue_buf[slot]->vb2_buf,
+				VB2_BUF_STATE_DONE);
+		vin->queue_buf[slot] = NULL;
 	} else {
-		/*
-		 * The single capturing requires an explicit capture
-		 * operation to fetch the next frame.
-		 */
-		if (!vin->continuous)
-			rvin_capture_on(vin);
+		/* Scratch buffer was used, dropping frame. */
+		vin_dbg(vin, "Dropping frame %u\n", vin->sequence);
 	}
+
+	vin->sequence++;
+
+	/* Prepare for next frame */
+	rvin_fill_hw_slot(vin, slot);
 done:
 	spin_unlock_irqrestore(&vin->qlock, flags);
 
@@ -1059,13 +981,6 @@ static void rvin_buffer_queue(struct vb2_buffer *vb)
 
 	list_add_tail(to_buf_list(vbuf), &vin->buf_list);
 
-	/*
-	 * If capture is stalled add buffer to HW and restart
-	 * capturing if HW is ready to continue.
-	 */
-	if (vin->state == STALLED)
-		rvin_capture_start(vin);
-
 	spin_unlock_irqrestore(&vin->qlock, flags);
 }
 
@@ -1076,6 +991,17 @@ static int rvin_start_streaming(struct vb2_queue *vq, unsigned int count)
 	unsigned long flags;
 	int ret;
 
+	/* Allocate scratch buffer. */
+	vin->scratch = dma_alloc_coherent(vin->dev, vin->format.sizeimage,
+					  &vin->scratch_phys, GFP_KERNEL);
+	if (!vin->scratch) {
+		spin_lock_irqsave(&vin->qlock, flags);
+		return_all_buffers(vin, VB2_BUF_STATE_QUEUED);
+		spin_unlock_irqrestore(&vin->qlock, flags);
+		vin_err(vin, "Failed to allocate scratch buffer\n");
+		return -ENOMEM;
+	}
+
 	sd = vin_to_source(vin);
 	v4l2_subdev_call(sd, video, s_stream, 1);
 
@@ -1091,6 +1017,10 @@ static int rvin_start_streaming(struct vb2_queue *vq, unsigned int count)
 
 	spin_unlock_irqrestore(&vin->qlock, flags);
 
+	if (ret)
+		dma_free_coherent(vin->dev, vin->format.sizeimage, vin->scratch,
+				  vin->scratch_phys);
+
 	return ret;
 }
 
@@ -1141,6 +1071,10 @@ static void rvin_stop_streaming(struct vb2_queue *vq)
 
 	/* disable interrupts */
 	rvin_disable_interrupts(vin);
+
+	/* Free scratch buffer. */
+	dma_free_coherent(vin->dev, vin->format.sizeimage, vin->scratch,
+			  vin->scratch_phys);
 }
 
 static const struct vb2_ops rvin_qops = {
@@ -1189,7 +1123,7 @@ int rvin_dma_probe(struct rvin_dev *vin, int irq)
 	q->ops = &rvin_qops;
 	q->mem_ops = &vb2_dma_contig_memops;
 	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
-	q->min_buffers_needed = 1;
+	q->min_buffers_needed = 4;
 	q->dev = vin->dev;
 
 	ret = vb2_queue_init(q);