From 5c9142a8063f71233b25d94ae0d73e7dcf9d2a1d Mon Sep 17 00:00:00 2001 From: Tomi Valkeinen Date: Thu, 18 Dec 2025 10:39:37 +0200 Subject: [PATCH] dmaengine: xilinx_dma: Add support for residue on direct AXIDMA S2MM 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 Reviewed-by: Suraj Gupta Link: https://patch.msgid.link/20251218-xilinx-dma-residue-fix-v1-1-7cd221d69d6b@ideasonboard.com Signed-off-by: Vinod Koul --- drivers/dma/xilinx/xilinx_dma.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c index fabff602065f6..64b3fba4e44fc 100644 --- a/drivers/dma/xilinx/xilinx_dma.c +++ b/drivers/dma/xilinx/xilinx_dma.c @@ -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; -- 2.47.3