ARM: OMAP: Proper handling of DMA4_IRQSTATUS_L0

The register bits are reset by writing one. Remove the unneeded reads and
fix writes to not clear too many bits.

Signed-off-by: Timo Teras <timo.teras@solidboot.com>
Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 3 insertions, 11 deletions

diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index bb045e5ddbd8..f3f84fbf8b87 100644
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -557,7 +557,7 @@ int omap_request_dma(int dev_id, const char *dev_name,
                 omap_enable_channel_irq(free_ch);
                 /* Clear the CSR register and IRQ status register */
                 OMAP_DMA_CSR_REG(free_ch) = OMAP2_DMA_CSR_CLEAR_MASK;
-                omap_writel(~0x0, OMAP_DMA4_IRQSTATUS_L0);
+                omap_writel(1 << free_ch, OMAP_DMA4_IRQSTATUS_L0);
         }
 
         *dma_ch_out = free_ch;
@@ -597,10 +597,7 @@ void omap_free_dma(int lch)
 
                 /* Clear the CSR register and IRQ status register */
                 OMAP_DMA_CSR_REG(lch) = OMAP2_DMA_CSR_CLEAR_MASK;
-
-                val = omap_readl(OMAP_DMA4_IRQSTATUS_L0);
-                val |= 1 << lch;
-                omap_writel(val, OMAP_DMA4_IRQSTATUS_L0);
+                omap_writel(1 << lch, OMAP_DMA4_IRQSTATUS_L0);
 
                 /* Disable all DMA interrupts for the channel. */
                 OMAP_DMA_CICR_REG(lch) = 0;
@@ -927,7 +924,6 @@ static irqreturn_t omap1_dma_irq_handler(int irq, void *dev_id)
 static int omap2_dma_handle_ch(int ch)
 {
         u32 status = OMAP_DMA_CSR_REG(ch);
-        u32 val;
 
         if (!status)
                 return 0;
@@ -948,11 +944,7 @@ static int omap2_dma_handle_ch(int ch)
                        dma_chan[ch].dev_id);
 
         OMAP_DMA_CSR_REG(ch) = OMAP2_DMA_CSR_CLEAR_MASK;
-
-        val = omap_readl(OMAP_DMA4_IRQSTATUS_L0);
-        /* ch in this function is from 0-31 while in register it is 1-32 */
-        val = 1 << (ch);
-        omap_writel(val, OMAP_DMA4_IRQSTATUS_L0);
+        omap_writel(1 << ch, OMAP_DMA4_IRQSTATUS_L0);
 
         if (likely(dma_chan[ch].callback != NULL))
                 dma_chan[ch].callback(ch, status, dma_chan[ch].data);