This is a note to let you know that I've just added the patch titled dmaengine: at_xdmac: Move the free desc to the tail of the desc list to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dmaengine-at_xdmac-move-the-free-desc-to-the-tail-of.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c4756066793ffa30d7265aef3b158e6076186a7e Author: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx> Date: Wed Dec 15 13:01:09 2021 +0200 dmaengine: at_xdmac: Move the free desc to the tail of the desc list [ Upstream commit 801db90bf294f647b967e8d99b9ae121bea63d0d ] 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: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20211215110115.191749-7-tudor.ambarus@xxxxxxxxxxxxx Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx> Stable-dep-of: 44fe8440bda5 ("dmaengine: at_xdmac: do not resume channels paused by consumers") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index 80c609aa2a91c..b45437aab1434 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -732,7 +732,8 @@ 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; } @@ -820,7 +821,8 @@ 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; } @@ -1054,8 +1056,8 @@ at_xdmac_prep_interleaved(struct dma_chan *chan, src_addr, dst_addr, xt, chunk); if (!desc) { - list_splice_init(&first->descs_list, - &atchan->free_descs_list); + list_splice_tail_init(&first->descs_list, + &atchan->free_descs_list); return NULL; } @@ -1135,7 +1137,8 @@ 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; } @@ -1311,8 +1314,8 @@ 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, - &atchan->free_descs_list); + list_splice_tail_init(&first->descs_list, + &atchan->free_descs_list); if (!first) first = desc; @@ -1709,7 +1712,8 @@ 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); } @@ -1858,7 +1862,8 @@ 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);