From: Tudor Ambarus tudor.ambarus@microchip.com
[ 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@microchip.com Link: https://lore.kernel.org/r/20211215110115.191749-7-tudor.ambarus@microchip.co... Signed-off-by: Vinod Koul vkoul@kernel.org Stable-dep-of: 4d43acb145c3 ("dmaengine: at_xdmac: fix potential Oops in at_xdmac_prep_interleaved()") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma/at_xdmac.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index 8af1c0fd3a736..96559c5df944d 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -678,7 +678,8 @@ 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; }
@@ -766,7 +767,8 @@ 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; } @@ -998,8 +1000,8 @@ 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; }
@@ -1077,7 +1079,8 @@ 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; }
@@ -1251,8 +1254,8 @@ 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; @@ -1649,7 +1652,8 @@ 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); } @@ -1798,7 +1802,8 @@ 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);