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dmaengine: xilinx_dma: Add support for residue on direct AXIDMA S2MM

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AXIDMA IP supports reporting the amount of bytes transferred on the S2MM
channel in direct mode (i.e. non-SG), but the driver does not. Thus the
driver always reports that all of the buffer was filled.

Add xilinx_dma_get_residue_axidma_direct_s2mm() which gets the residue
amount for direct AXIDMA for S2MM direction.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Suraj Gupta <suraj.gupta2@amd.com>
Link: https://patch.msgid.link/20251218-xilinx-dma-residue-fix-v1-1-7cd221d69d6b@ideasonboard.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Tomi Valkeinen 2025-12-18 10:39:37 +02:00 • committed by Vinod Koul
parent 7105e968d1
commit 5c9142a806
1 changed files with 21 additions and 0 deletions
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21
drivers/dma/xilinx/xilinx_dma.c
View file

@ -1021,6 +1021,24 @@ static u32 xilinx_dma_get_residue(struct xilinx_dma_chan *chan,
return residue;
}
static u32
xilinx_dma_get_residue_axidma_direct_s2mm(struct xilinx_dma_chan *chan,
struct xilinx_dma_tx_descriptor *desc)
{
struct xilinx_axidma_tx_segment *seg;
struct xilinx_axidma_desc_hw *hw;
u32 finished_len;
finished_len = dma_ctrl_read(chan, XILINX_DMA_REG_BTT);
seg = list_first_entry(&desc->segments, struct xilinx_axidma_tx_segment,
node);
hw = &seg->hw;
return hw->control - finished_len;
}
/**
* xilinx_dma_chan_handle_cyclic - Cyclic dma callback
* @chan: Driver specific dma channel
@ -1732,6 +1750,9 @@ static void xilinx_dma_complete_descriptor(struct xilinx_dma_chan *chan)
if (chan->has_sg && chan->xdev->dma_config->dmatype !=
XDMA_TYPE_VDMA)
desc->residue = xilinx_dma_get_residue(chan, desc);
else if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA &&
chan->direction == DMA_DEV_TO_MEM && !chan->has_sg)
desc->residue = xilinx_dma_get_residue_axidma_direct_s2mm(chan, desc);
else
desc->residue = 0;
desc->err = chan->err;