Messages in this thread | | | Subject | Re: [PATCH 01/15] iio: buffer-dma: Get rid of incoming/outgoing queues | From | Lars-Peter Clausen <> | Date | Sun, 21 Nov 2021 17:23:35 +0100 |
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On 11/15/21 3:19 PM, Paul Cercueil wrote: > The buffer-dma code was using two queues, incoming and outgoing, to > manage the state of the blocks in use. > > While this totally works, it adds some complexity to the code, > especially since the code only manages 2 blocks. It is much easier to > just check each block's state manually, and keep a counter for the next > block to dequeue. > > Since the new DMABUF based API wouldn't use these incoming and outgoing > queues anyway, getting rid of them now makes the upcoming changes > simpler. > > Signed-off-by: Paul Cercueil <paul@crapouillou.net> The outgoing queue is going to be replaced by fences, but I think we need to keep the incoming queue. > [...] > @@ -442,28 +435,33 @@ EXPORT_SYMBOL_GPL(iio_dma_buffer_disable); > static void iio_dma_buffer_enqueue(struct iio_dma_buffer_queue *queue, > struct iio_dma_buffer_block *block) > { > - if (block->state == IIO_BLOCK_STATE_DEAD) { > + if (block->state == IIO_BLOCK_STATE_DEAD) > iio_buffer_block_put(block); > - } else if (queue->active) { > + else if (queue->active) > iio_dma_buffer_submit_block(queue, block); > - } else { > + else > block->state = IIO_BLOCK_STATE_QUEUED; > - list_add_tail(&block->head, &queue->incoming); If iio_dma_buffer_enqueue() is called with a dmabuf and the buffer is not active, it will be marked as queued, but we don't actually keep a reference to it anywhere. It will never be submitted to the DMA, and it will never be signaled as completed.
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