| Message ID | 1481810617-7650-3-git-send-email-shawnguo@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
2016-12-15 22:03 GMT+08:00 Shawn Guo <shawnguo@kernel.org>: > From: Shawn Guo <shawn.guo@linaro.org> > > 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 <shawn.guo@linaro.org> > --- > drivers/dma/zx_dma.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > Reviewed-by: Jun Nie <jun.nie@linaro.org>
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 */