1 files changed, 23 insertions, 21 deletions

diff --git a/drivers/iio/buffer/industrialio-buffer-dma.c b/drivers/iio/buffer/industrialio-buffer-dma.c
index d348af8b9705..1fc91467d1aa 100644
--- a/drivers/iio/buffer/industrialio-buffer-dma.c
+++ b/drivers/iio/buffer/industrialio-buffer-dma.c
@@ -179,7 +179,7 @@ static struct iio_dma_buffer_block *iio_dma_buffer_alloc_block(
 	}
 
 	block->size = size;
-	block->state = IIO_BLOCK_STATE_DEQUEUED;
+	block->state = IIO_BLOCK_STATE_DONE;
 	block->queue = queue;
 	INIT_LIST_HEAD(&block->head);
 	kref_init(&block->kref);
@@ -191,16 +191,8 @@ static struct iio_dma_buffer_block *iio_dma_buffer_alloc_block(
 
 static void _iio_dma_buffer_block_done(struct iio_dma_buffer_block *block)
 {
-	struct iio_dma_buffer_queue *queue = block->queue;
-
-	/*
-	 * The buffer has already been freed by the application, just drop the
-	 * reference.
-	 */
-	if (block->state != IIO_BLOCK_STATE_DEAD) {
+	if (block->state != IIO_BLOCK_STATE_DEAD)
 		block->state = IIO_BLOCK_STATE_DONE;
-		list_add_tail(&block->head, &queue->outgoing);
-	}
 }
 
 /**
@@ -261,7 +253,6 @@ static bool iio_dma_block_reusable(struct iio_dma_buffer_block *block)
 	 * not support abort and has not given back the block yet.
 	 */
 	switch (block->state) {
-	case IIO_BLOCK_STATE_DEQUEUED:
 	case IIO_BLOCK_STATE_QUEUED:
 	case IIO_BLOCK_STATE_DONE:
 		return true;
@@ -317,7 +308,6 @@ int iio_dma_buffer_request_update(struct iio_buffer *buffer)
 	 * dead. This means we can reset the lists without having to fear
 	 * corrution.
 	 */
-	INIT_LIST_HEAD(&queue->outgoing);
 	spin_unlock_irq(&queue->list_lock);
 
 	INIT_LIST_HEAD(&queue->incoming);
@@ -456,14 +446,20 @@ static struct iio_dma_buffer_block *iio_dma_buffer_dequeue(
 	struct iio_dma_buffer_queue *queue)
 {
 	struct iio_dma_buffer_block *block;
+	unsigned int idx;
 
 	spin_lock_irq(&queue->list_lock);
-	block = list_first_entry_or_null(&queue->outgoing, struct
-		iio_dma_buffer_block, head);
-	if (block != NULL) {
-		list_del(&block->head);
-		block->state = IIO_BLOCK_STATE_DEQUEUED;
+
+	idx = queue->fileio.next_dequeue;
+	block = queue->fileio.blocks[idx];
+
+	if (block->state == IIO_BLOCK_STATE_DONE) {
+		idx = (idx + 1) % ARRAY_SIZE(queue->fileio.blocks);
+		queue->fileio.next_dequeue = idx;
+	} else {
+		block = NULL;
 	}
+
 	spin_unlock_irq(&queue->list_lock);
 
 	return block;
@@ -539,6 +535,7 @@ size_t iio_dma_buffer_data_available(struct iio_buffer *buf)
 	struct iio_dma_buffer_queue *queue = iio_buffer_to_queue(buf);
 	struct iio_dma_buffer_block *block;
 	size_t data_available = 0;
+	unsigned int i;
 
 	/*
 	 * For counting the available bytes we'll use the size of the block not
@@ -552,8 +549,15 @@ size_t iio_dma_buffer_data_available(struct iio_buffer *buf)
 		data_available += queue->fileio.active_block->size;
 
 	spin_lock_irq(&queue->list_lock);
-	list_for_each_entry(block, &queue->outgoing, head)
-		data_available += block->size;
+
+	for (i = 0; i < ARRAY_SIZE(queue->fileio.blocks); i++) {
+		block = queue->fileio.blocks[i];
+
+		if (block != queue->fileio.active_block
+		    && block->state == IIO_BLOCK_STATE_DONE)
+			data_available += block->size;
+	}
+
 	spin_unlock_irq(&queue->list_lock);
 	mutex_unlock(&queue->lock);
 
@@ -617,7 +621,6 @@ int iio_dma_buffer_init(struct iio_dma_buffer_queue *queue,
 	queue->ops = ops;
 
 	INIT_LIST_HEAD(&queue->incoming);
-	INIT_LIST_HEAD(&queue->outgoing);
 
 	mutex_init(&queue->lock);
 	spin_lock_init(&queue->list_lock);
@@ -645,7 +648,6 @@ void iio_dma_buffer_exit(struct iio_dma_buffer_queue *queue)
 			continue;
 		queue->fileio.blocks[i]->state = IIO_BLOCK_STATE_DEAD;
 	}
-	INIT_LIST_HEAD(&queue->outgoing);
 	spin_unlock_irq(&queue->list_lock);
 
 	INIT_LIST_HEAD(&queue->incoming);