From 6792a3f47a2e42d7164292bf7f1a55cfc4c91652 Mon Sep 17 00:00:00 2001 From: Anton Arapov Date: Fri, 8 Jun 2012 12:58:00 +0200 Subject: fedora kernel: b920e9b748c595f970bf80ede7832d39f8d567da Signed-off-by: Anton Arapov --- arch/arm/plat-omap/dma.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'arch/arm/plat-omap/dma.c') diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index 002fb4d96bb..c58d896cd5c 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -36,7 +36,6 @@ #include #include -#include #include #include @@ -164,6 +163,8 @@ static inline void set_gdma_dev(int req, int dev) } #else #define set_gdma_dev(req, dev) do {} while (0) +#define omap_readl(reg) 0 +#define omap_writel(val, reg) do {} while (0) #endif void omap_set_dma_priority(int lch, int dst_port, int priority) @@ -915,6 +916,13 @@ 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; @@ -964,6 +972,13 @@ 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[dma_lch_count]; @@ -2125,7 +2140,7 @@ static int __devexit omap_system_dma_remove(struct platform_device *pdev) static struct platform_driver omap_system_dma_driver = { .probe = omap_system_dma_probe, - .remove = omap_system_dma_remove, + .remove = __devexit_p(omap_system_dma_remove), .driver = { .name = "omap_dma_system" }, -- cgit