From 776c8943f2766f2819fafd88fdfbaf418ecd6e41 Mon Sep 17 00:00:00 2001 From: Ira Snyder Date: Fri, 15 May 2009 11:33:20 -0700 Subject: [PATCH] fsldma: snooping is not enabled for last entry in descriptor chain On the 83xx controller, snooping is necessary for the DMA controller to ensure cache coherence with the CPU when transferring to/from RAM. The last descriptor in a chain will always have the End-of-Chain interrupt bit set, so we can set the snoop bit while adding the End-of-Chain interrupt bit. Signed-off-by: Ira W. Snyder Signed-off-by: Li Yang --- drivers/dma/fsldma.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index 7313a1ae5f83..ff9194d7ebb7 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -179,9 +179,14 @@ static void dma_halt(struct fsl_dma_chan *fsl_chan) static void set_ld_eol(struct fsl_dma_chan *fsl_chan, struct fsl_desc_sw *desc) { + u64 snoop_bits; + + snoop_bits = ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX) + ? FSL_DMA_SNEN : 0; + desc->hw.next_ln_addr = CPU_TO_DMA(fsl_chan, - DMA_TO_CPU(fsl_chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL, - 64); + DMA_TO_CPU(fsl_chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL + | snoop_bits, 64); } static void append_ld_queue(struct fsl_dma_chan *fsl_chan, -- 2.20.1