[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>

1 files changed, 10 insertions, 8 deletions

diff --git a/arch/arm/mach-pxa/dma.c b/arch/arm/mach-pxa/dma.c
index b1514fb20d3a..7de17fc5d54b 100644
--- 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;