From 156ae09245c4c49c8eb4a0898411ee260966331d Mon Sep 17 00:00:00 2001 From: Shawn Guo Date: Thu, 15 Dec 2016 22:03:37 +0800 Subject: dmaengine: zx: fix residue calculation The dma residue is defined as the free space to end of transfer buffer, which could be multiple segments chained together. So the residue calculation in zx_dma_tx_status() works for both slave_sg and cyclic case. But unfortunately, the 'index' is wrong. It should plus one, because the current segment is already occupied and shouldn't be counted into free space. This fixes the HDMI audio noise issue we see on ZX296718 with SPDIF interface. Signed-off-by: Shawn Guo Reviewed-by: Jun Nie Signed-off-by: Vinod Koul --- drivers/dma/zx_dma.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/dma/zx_dma.c b/drivers/dma/zx_dma.c index 33155c6816cc..42ff3e66c1e1 100644 --- a/drivers/dma/zx_dma.c +++ b/drivers/dma/zx_dma.c @@ -365,7 +365,8 @@ static enum dma_status zx_dma_tx_status(struct dma_chan *chan, bytes = 0; clli = zx_dma_get_curr_lli(p); - index = (clli - ds->desc_hw_lli) / sizeof(struct zx_desc_hw); + index = (clli - ds->desc_hw_lli) / + sizeof(struct zx_desc_hw) + 1; for (; index < ds->desc_num; index++) { bytes += ds->desc_hw[index].src_x; /* end of lli */ -- cgit v1.2.3