[PATCH] dmaengine: fsldma: set BWC, DAHTS and SAHTS values correctly

Thomas Breitung thomas.breitung at izt-labs.de
Tue Jun 20 00:40:04 AEST 2017


The bits of BWC, DAHTS and SAHTS in the DMA mode register must be cleared
before a new value can be or-ed in.

Signed-off-by: Thomas Breitung <thomas.breitung at izt-labs.de>
Signed-off-by: Wolfgang Ocker <weo at reccoware.de>
---
 drivers/dma/fsldma.c | 5 ++++-
 drivers/dma/fsldma.h | 4 ++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index 51c75bf2b9b6..3b8b752ede2d 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -269,6 +269,7 @@ static void fsl_chan_set_src_loop_size(struct fsldma_chan *chan, int size)
 	case 2:
 	case 4:
 	case 8:
+		mode &= ~FSL_DMA_MR_SAHTS_MASK;
 		mode |= FSL_DMA_MR_SAHE | (__ilog2(size) << 14);
 		break;
 	}
@@ -301,6 +302,7 @@ static void fsl_chan_set_dst_loop_size(struct fsldma_chan *chan, int size)
 	case 2:
 	case 4:
 	case 8:
+		mode &= ~FSL_DMA_MR_DAHTS_MASK;
 		mode |= FSL_DMA_MR_DAHE | (__ilog2(size) << 16);
 		break;
 	}
@@ -327,7 +329,8 @@ static void fsl_chan_set_request_count(struct fsldma_chan *chan, int size)
 	BUG_ON(size > 1024);
 
 	mode = get_mr(chan);
-	mode |= (__ilog2(size) << 24) & 0x0f000000;
+	mode &= ~FSL_DMA_MR_BWC_MASK;
+	mode |= (__ilog2(size) << 24) & FSL_DMA_MR_BWC_MASK;
 
 	set_mr(chan, mode);
 }
diff --git a/drivers/dma/fsldma.h b/drivers/dma/fsldma.h
index 31bffccdcc75..4787d485dd76 100644
--- a/drivers/dma/fsldma.h
+++ b/drivers/dma/fsldma.h
@@ -36,6 +36,10 @@
 #define FSL_DMA_MR_DAHE		0x00002000
 #define FSL_DMA_MR_SAHE		0x00001000
 
+#define FSL_DMA_MR_SAHTS_MASK	0x0000C000
+#define FSL_DMA_MR_DAHTS_MASK	0x00030000
+#define FSL_DMA_MR_BWC_MASK	0x0f000000
+
 /*
  * Bandwidth/pause control determines how many bytes a given
  * channel is allowed to transfer before the DMA engine pauses
-- 
2.13.0



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