Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
dmaengine: dma-axi-dmac: Add helper for getting next desc
Add a new helper for getting the next valid struct axi_dmac_desc. This
will be extended in follow up patches to support to gracefully terminate
cyclic transfers.
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-3-0db27b4be95a@analog.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
authored by
Nuno Sá
and committed by
Vinod Koul
c60990ba
ac85913a
+23
-10
+23
-10
drivers/dma/dma-axi-dmac.c
+23
-10
drivers/dma/dma-axi-dmac.c
···
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return true;
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}
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+
static struct axi_dmac_desc *axi_dmac_get_next_desc(struct axi_dmac *dmac,
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struct axi_dmac_chan *chan)
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{
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struct virt_dma_desc *vdesc;
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struct axi_dmac_desc *desc;
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+
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if (chan->next_desc)
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return chan->next_desc;
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vdesc = vchan_next_desc(&chan->vchan);
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if (!vdesc)
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return NULL;
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list_move_tail(&vdesc->node, &chan->active_descs);
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desc = to_axi_dmac_desc(vdesc);
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chan->next_desc = desc;
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return desc;
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}
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+
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static void axi_dmac_start_transfer(struct axi_dmac_chan *chan)
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{
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struct axi_dmac *dmac = chan_to_axi_dmac(chan);
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struct virt_dma_desc *vdesc;
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struct axi_dmac_desc *desc;
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struct axi_dmac_sg *sg;
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unsigned int flags = 0;
···
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if (val) /* Queue is full, wait for the next SOT IRQ */
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return;
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desc = chan->next_desc;
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desc = axi_dmac_get_next_desc(dmac, chan);
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if (!desc)
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return;
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-
if (!desc) {
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vdesc = vchan_next_desc(&chan->vchan);
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if (!vdesc)
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return;
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list_move_tail(&vdesc->node, &chan->active_descs);
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desc = to_axi_dmac_desc(vdesc);
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chan->next_desc = desc;
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}
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sg = &desc->sg[desc->num_submitted];
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/* Already queued in cyclic mode. Wait for it to finish */