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dmaengine: dma-axi-dmac: Add helper for getting next desc

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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>
This commit is contained in:
Nuno Sá
2026-03-03 10:25:02 +00:00
committed by Vinod Koul
parent ac85913ab7
commit c60990ba1f
1 changed files with 23 additions and 10 deletions
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33
drivers/dma/dma-axi-dmac.c
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@@ -227,10 +227,29 @@ static bool axi_dmac_check_addr(struct axi_dmac_chan *chan, dma_addr_t addr)
return true;
}
static struct axi_dmac_desc *axi_dmac_get_next_desc(struct axi_dmac *dmac,
struct axi_dmac_chan *chan)
{
struct virt_dma_desc *vdesc;
struct axi_dmac_desc *desc;
if (chan->next_desc)
return chan->next_desc;
vdesc = vchan_next_desc(&chan->vchan);
if (!vdesc)
return NULL;
list_move_tail(&vdesc->node, &chan->active_descs);
desc = to_axi_dmac_desc(vdesc);
chan->next_desc = desc;
return desc;
}
static void axi_dmac_start_transfer(struct axi_dmac_chan *chan)
{
struct axi_dmac *dmac = chan_to_axi_dmac(chan);
struct virt_dma_desc *vdesc;
struct axi_dmac_desc *desc;
struct axi_dmac_sg *sg;
unsigned int flags = 0;
@@ -240,16 +259,10 @@ static void axi_dmac_start_transfer(struct axi_dmac_chan *chan)
if (val) /* Queue is full, wait for the next SOT IRQ */
return;
desc = chan->next_desc;
desc = axi_dmac_get_next_desc(dmac, chan);
if (!desc)
return;
if (!desc) {
vdesc = vchan_next_desc(&chan->vchan);
if (!vdesc)
return;
list_move_tail(&vdesc->node, &chan->active_descs);
desc = to_axi_dmac_desc(vdesc);
chan->next_desc = desc;
}
sg = &desc->sg[desc->num_submitted];
/* Already queued in cyclic mode. Wait for it to finish */