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authorSonic Zhang <sonic.zhang@analog.com>2009-06-01 00:49:32 -0400
committerMike Frysinger <vapier@gentoo.org>2009-06-12 06:11:57 -0400
commitea8538a039607cd959d28ed10086484e051ce7db (patch)
treeda311d3d0e84af6398a58384fe937684df8dcdcc /arch/blackfin
parent9b9bfded623cffb4259b95e5419404015dba361f (diff)
downloadlinux-2.6.34-ux500-ea8538a039607cd959d28ed10086484e051ce7db.tar.gz
Blackfin: add SSYNC to set_dma_sg() for descriptor fetching
Make sure the internal core buffers are flushed before telling the DMA engine to fetch the descriptor structure so that it gets the right values. Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'arch/blackfin')
-rw-r--r--arch/blackfin/include/asm/dma.h8
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/blackfin/include/asm/dma.h b/arch/blackfin/include/asm/dma.h
index 46c56185417..c9a59622e23 100644
--- a/arch/blackfin/include/asm/dma.h
+++ b/arch/blackfin/include/asm/dma.h
@@ -206,10 +206,16 @@ static inline unsigned long get_dma_curr_addr(unsigned int channel)
static inline void set_dma_sg(unsigned int channel, struct dmasg *sg, int ndsize)
{
+ /* Make sure the internal data buffers in the core are drained
+ * so that the DMA descriptors are completely written when the
+ * DMA engine goes to fetch them below.
+ */
+ SSYNC();
+
+ dma_ch[channel].regs->next_desc_ptr = sg;
dma_ch[channel].regs->cfg =
(dma_ch[channel].regs->cfg & ~(0xf << 8)) |
((ndsize & 0xf) << 8);
- dma_ch[channel].regs->next_desc_ptr = sg;
}
static inline int dma_channel_active(unsigned int channel)