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authorArnd Bergmann <arnd@arndb.de>2012-05-11 17:15:31 +0200
committerArnd Bergmann <arnd@arndb.de>2012-05-11 17:15:31 +0200
commit93c6d8927fa692faef3d7d945bd4fe84b0185ad4 (patch)
tree0a971c86114656ec4e39f7789d9faeb70432c36a /arch/arm/plat-omap/dma.c
parentea01d31a07ae182028d2398380948f5a4ee09953 (diff)
parent50260924afd4b745bfb6e5f1caee381a1875fc31 (diff)
Merge branch 'clk/mxs' of git://git.linaro.org/people/shawnguo/linux-2.6 into next/clock
Shawn Guo <shawn.guo@linaro.org> writes: mxs common clk porting for v3.5. It depends on the following two branches. [1] git://git.linaro.org/people/mturquette/linux.git clk-next [2] http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-arm.git clkdev As the mxs device tree conversion will constantly touch clock files, to save the conflicts, the updated mxs/dt branch coming later will based on this pull-request. * 'clk/mxs' of git://git.linaro.org/people/shawnguo/linux-2.6: ARM: mxs: remove now unused timer_clk argument from mxs_timer_init ARM: mxs: remove old clock support ARM: mxs: switch to common clk framework ARM: mxs: change the lookup name for fec phy clock ARM: mxs: request clock for timer clk: mxs: add clock support for imx28 clk: mxs: add clock support for imx23 clk: mxs: add mxs specific clocks Includes an update to Linux 3.4-rc6 Conflicts: drivers/clk/Makefile Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/arm/plat-omap/dma.c')
-rw-r--r--arch/arm/plat-omap/dma.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index ecdb3da0dea9..c58d896cd5c3 100644
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -916,6 +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;
@@ -965,6 +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];