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| author | Olof Johansson <olof@lixom.net> | 2012-05-09 13:31:01 +0400 |
|---|---|---|
| committer | Olof Johansson <olof@lixom.net> | 2012-05-09 13:31:01 +0400 |
| commit | d5a2a1ba838f60d92bf67c5eef533e95453752cb (patch) | |
| tree | f6436b5e2b430197f37e49ffff23e91ef694b303 /arch/arm/plat-omap/dma.c | |
| parent | e1851240a891a305946814587497f121b900b4be (diff) | |
| parent | d48b97b403d23f6df0b990cee652bdf9a52337a3 (diff) | |
| download | linux-d5a2a1ba838f60d92bf67c5eef533e95453752cb.tar.xz | |
Merge tag 'v3.4-rc6' into next/cleanup
Linux 3.4-rc6
Resolve conflict where an u5500 file had a bugfix go in, but was
deleted in the branch staged for next merge window.
Signed-off-by: Olof Johansson <olof@lixom.net>
Diffstat (limited to 'arch/arm/plat-omap/dma.c')
| -rw-r--r-- | arch/arm/plat-omap/dma.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index 612227efe34f..987e6101267d 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -925,6 +925,13 @@ void omap_start_dma(int lch) l |= OMAP_DMA_CCR_BUFFERING_DISABLE; l |= OMAP_DMA_CCR_EN; + /* + * As dma_write() uses IO accessors which are weakly ordered, there + * is no guarantee that data in coherent DMA memory will be visible + * to the DMA device. Add a memory barrier here to ensure that any + * such data is visible prior to enabling DMA. + */ + mb(); p->dma_write(l, CCR, lch); dma_chan[lch].flags |= OMAP_DMA_ACTIVE; @@ -974,6 +981,13 @@ void omap_stop_dma(int lch) p->dma_write(l, CCR, lch); } + /* + * Ensure that data transferred by DMA is visible to any access + * after DMA has been disabled. This is important for coherent + * DMA regions. + */ + mb(); + if (!omap_dma_in_1510_mode() && dma_chan[lch].next_lch != -1) { int next_lch, cur_lch = lch; char dma_chan_link_map[MAX_LOGICAL_DMA_CH_COUNT]; |