Commit 801db90b authored by Tudor Ambarus's avatar Tudor Ambarus Committed by Vinod Koul
Browse files

dmaengine: at_xdmac: Move the free desc to the tail of the desc list 



Move the free desc to the tail of the list, so that the sequence of
descriptors is more track-able in case of debug. One would know which
descriptor should come next and could easier catch concurrency over
descriptors for example. virt-dma uses list_splice_tail_init() as well,
follow the core driver.

Signed-off-by: default avatarTudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20211215110115.191749-7-tudor.ambarus@microchip.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent b63e5cb9

drivers/dma/at_xdmac.c

+14 −9
Original line number Diff line number Diff line
@@ -729,7 +729,8 @@ at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 
		if (!desc) {

			dev_err(chan2dev(chan), "can't get descriptor\n");

			if (first)

				list_splice_init(&first->descs_list, &atchan->free_descs_list);

				list_splice_tail_init(&first->descs_list,

						      &atchan->free_descs_list);

			goto spin_unlock;

		}
@@ -817,7 +818,8 @@ at_xdmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, 
		if (!desc) {

			dev_err(chan2dev(chan), "can't get descriptor\n");

			if (first)

				list_splice_init(&first->descs_list, &atchan->free_descs_list);

				list_splice_tail_init(&first->descs_list,

						      &atchan->free_descs_list);

			spin_unlock_irqrestore(&atchan->lock, irqflags);

			return NULL;

		}
@@ -1051,7 +1053,7 @@ at_xdmac_prep_interleaved(struct dma_chan *chan, 
							       src_addr, dst_addr,

							       xt, chunk);

			if (!desc) {

				list_splice_init(&first->descs_list,

				list_splice_tail_init(&first->descs_list,

						      &atchan->free_descs_list);

				return NULL;

			}
@@ -1132,7 +1134,8 @@ at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, 
		if (!desc) {

			dev_err(chan2dev(chan), "can't get descriptor\n");

			if (first)

				list_splice_init(&first->descs_list, &atchan->free_descs_list);

				list_splice_tail_init(&first->descs_list,

						      &atchan->free_descs_list);

			return NULL;

		}
@@ -1308,7 +1311,7 @@ at_xdmac_prep_dma_memset_sg(struct dma_chan *chan, struct scatterlist *sgl, 
						   sg_dma_len(sg),

						   value);

		if (!desc && first)

			list_splice_init(&first->descs_list,

			list_splice_tail_init(&first->descs_list,

					      &atchan->free_descs_list);



		if (!first)
@@ -1701,7 +1704,8 @@ static void at_xdmac_tasklet(struct tasklet_struct *t) 


		spin_lock_irq(&atchan->lock);

		/* Move the xfer descriptors into the free descriptors list. */

		list_splice_init(&desc->descs_list, &atchan->free_descs_list);

		list_splice_tail_init(&desc->descs_list,

				      &atchan->free_descs_list);

		at_xdmac_advance_work(atchan);

		spin_unlock_irq(&atchan->lock);

	}
@@ -1850,7 +1854,8 @@ static int at_xdmac_device_terminate_all(struct dma_chan *chan) 
	/* Cancel all pending transfers. */

	list_for_each_entry_safe(desc, _desc, &atchan->xfers_list, xfer_node) {

		list_del(&desc->xfer_node);

		list_splice_init(&desc->descs_list, &atchan->free_descs_list);

		list_splice_tail_init(&desc->descs_list,

				      &atchan->free_descs_list);

	}



	clear_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status);