[ARM] pxa: stop and disable IRQ for each DMA channels at startup

Some broken bootloaders will leave the DMA channel state unclean, which
we should really initialize correctly here.

Signed-off-by: Eric Miao <eric.miao@marvell.com>

diff --git a/arch/arm/mach-pxa/dma.c b/arch/arm/mach-pxa/dma.c
index b1514fb..7de17fc 100644 (file)
--- a/arch/arm/mach-pxa/dma.c
+++ b/arch/arm/mach-pxa/dma.c
@@ -121,20 +121,22 @@ int __init pxa_init_dma(int num_ch)
        if (dma_channels == NULL)
                return -ENOMEM;
 
-       ret = request_irq(IRQ_DMA, dma_irq_handler, IRQF_DISABLED, "DMA", NULL);
-       if (ret) {
-               printk (KERN_CRIT "Wow!  Can't register IRQ for DMA\n");
-               kfree(dma_channels);
-               return ret;
-       }
-
        /* dma channel priorities on pxa2xx processors:
         * ch 0 - 3,  16 - 19  <--> (0) DMA_PRIO_HIGH
         * ch 4 - 7,  20 - 23  <--> (1) DMA_PRIO_MEDIUM
         * ch 8 - 15, 24 - 31  <--> (2) DMA_PRIO_LOW
         */
-       for (i = 0; i < num_ch; i++)
+       for (i = 0; i < num_ch; i++) {
+               DCSR(i) = 0;
                dma_channels[i].prio = min((i & 0xf) >> 2, DMA_PRIO_LOW);
+       }
+
+       ret = request_irq(IRQ_DMA, dma_irq_handler, IRQF_DISABLED, "DMA", NULL);
+       if (ret) {
+               printk (KERN_CRIT "Wow!  Can't register IRQ for DMA\n");
+               kfree(dma_channels);
+               return ret;
+       }
 
        num_dma_channels = num_ch;
        return 0;