From 04110caa6e1c5f92225c34a62d1bd7b6d276b85e Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Fri, 27 Feb 2009 11:38:28 -0800 Subject: [PATCH] This fixes the spurious interrupt issue on a DMA channel. In OMAP sDMA, contrast to the SDMA.DMA4_CSRi registers, the SDMA.DMA4_IRQSTATUS_Lj registers are updated regardless of the corresponding bits in the SDMA.DMA4_IRQENABLE_Lj registers. Since there are four sDMA interrupt lines and if more than one line is actively used by two concurrently running sDMA softwares modules,then the spurious interrupt can be observed on the other lines. Fix in this patch will only dispatch the relevant and enabled interrupts on a particular line thus perevting spurious IRQ. Signed-off-by: Santosh Shilimkar Acked By: Nishant Kamat cc: Tony Lindgren Signed-off-by: Tony Lindgren --- arch/arm/plat-omap/dma.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index e9b540805d7..3fd0e77bb9f 100755 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -1901,7 +1901,7 @@ static int omap2_dma_handle_ch(int ch) /* STATUS register count is from 1-32 while our is 0-31 */ static irqreturn_t omap2_dma_irq_handler(int irq, void *dev_id) { - u32 val; + u32 val, enable_reg; int i; val = dma_read(IRQSTATUS_L0); @@ -1910,6 +1910,8 @@ static irqreturn_t omap2_dma_irq_handler(int irq, void *dev_id) printk(KERN_WARNING "Spurious DMA IRQ\n"); return IRQ_HANDLED; } + enable_reg = dma_read(IRQENABLE_L0); + val &= enable_reg; /* Dispatch only relevant interrupts */ for (i = 0; i < dma_lch_count && val != 0; i++) { if (val & 1) omap2_dma_handle_ch(i); -- 2.41.1