From 320ce6f6fb3d95e02a183709e51d8a16a8b00e0a Mon Sep 17 00:00:00 2001 From: Juha Yrjola Date: Thu, 29 Jan 2009 08:57:12 -0800 Subject: ARM: OMAP: Fix race in OMAP2/3 DMA IRQ handling CSR must be cleared before invoking the callback. If the callback function starts a new, fast DMA transfer on the same channel, the completion status might lost if CSR is cleared after the callback invocation. Signed-off-by: Juha Yrjola Signed-off-by: Tony Lindgren --- arch/arm/plat-omap/dma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm/plat-omap') diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index e77373c39f8c..bec8e363d545 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -1888,11 +1888,11 @@ static int omap2_dma_handle_ch(int ch) status = dma_read(CSR(ch)); } + dma_write(status, CSR(ch)); + if (likely(dma_chan[ch].callback != NULL)) dma_chan[ch].callback(ch, status, dma_chan[ch].data); - dma_write(status, CSR(ch)); - return 0; } -- cgit v1.2.3