[PATCH] dmaengine: dw: clear LLP_[SD]_EN bits in last descriptor of a chain
From: Mans Rullgard
Date: Mon Dec 21 2015 - 14:10:47 EST
The datasheet requires that the LLP_[SD]_EN bits be cleared whenever
LLP.LOC is zero, i.e. in the last descriptor of a multi-block chain.
Make the driver do this.
Signed-off-by: Mans Rullgard <mans@xxxxxxxxx>
---
drivers/dma/dw/core.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 7067b6ddc1db..ca7cafc82f6b 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -751,6 +751,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
prev->lli.ctllo |= DWC_CTLL_INT_EN;
prev->lli.llp = 0;
+ prev->lli.ctllo &= ~(DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
first->txd.flags = flags;
first->total_len = len;
@@ -912,6 +913,7 @@ slave_sg_fromdev_fill_desc:
prev->lli.ctllo |= DWC_CTLL_INT_EN;
prev->lli.llp = 0;
+ prev->lli.ctllo &= ~(DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
first->total_len = total_len;
return &first->txd;
--
2.6.3
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