Messages in this thread | | | Date | Tue, 3 Jan 2012 17:46:39 +0000 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH v2 2/2] dma/imx-sdma: add wmb before enable a channel |
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On Sun, Jan 01, 2012 at 10:38:12PM +0800, Richard Zhao wrote: > dma_alloc_coherent memory may be bufferable. We need to add > nececcary memory barrier. > > Signed-off-by: Richard Zhao <richard.zhao@linaro.org> > --- > drivers/dma/imx-sdma.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c > index f8e87b5..9301bff 100644 > --- a/drivers/dma/imx-sdma.c > +++ b/drivers/dma/imx-sdma.c > @@ -394,6 +394,7 @@ static int sdma_config_ownership(struct sdma_channel *sdmac, > > static void sdma_enable_channel(struct sdma_engine *sdma, int channel) > { > + wmb(); > __raw_writel(1 << channel, sdma->regs + SDMA_H_START);
Use writel(). That's what it's there for:
#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE #define __iowmb() wmb() #endif #define writel_relaxed(v,c) ((void)__raw_writel((__force u32) \ cpu_to_le32(v),__mem_pci(c))) #define writel(v,c) ({ __iowmb(); writel_relaxed(v,c); })
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