From 5a6187d70f7fc0b55db49af4b2a0f35f34efd770 Mon Sep 17 00:00:00 2001 From: Daniel Silsby Date: Wed, 29 Aug 2018 23:32:53 +0200 Subject: [PATCH] dmaengine: dma-jz4780: Add missing residue DTC mask The 'dtc' word in jz DMA descriptors contains two fields: The lowest 24 bits are the transfer count, and upper 8 bits are the DOA offset to next descriptor. The upper 8 bits are now correctly masked off when computing residue in jz4780_dma_desc_residue(). Note that reads of the DTCn hardware reg are automatically masked this way. Signed-off-by: Daniel Silsby Signed-off-by: Paul Cercueil Tested-by: Mathieu Malaterre Signed-off-by: Vinod Koul --- drivers/dma/dma-jz4780.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c index 3a4d0a4b550d..bd3cecb800c5 100644 --- a/drivers/dma/dma-jz4780.c +++ b/drivers/dma/dma-jz4780.c @@ -616,7 +616,8 @@ static size_t jz4780_dma_desc_residue(struct jz4780_dma_chan *jzchan, residue = 0; for (i = next_sg; i < desc->count; i++) - residue += desc->desc[i].dtc << jzchan->transfer_shift; + residue += (desc->desc[i].dtc & GENMASK(23, 0)) << + jzchan->transfer_shift; if (next_sg != 0) { count = jz4780_dma_chn_readl(jzdma, jzchan->id, -- 2.30.2