omap: dma: Add read-back to DMA interrupt handler to avoid spuriousinterrupts

Flush the writes to IRQSTATUS_L0 register in the DMA interrupt handler by reading the register
directly after write. This prevents the spurious DMA interrupts noted when using VDD_OPP 1

Signed-off-by: Mathias Nyman <mathias.nyman@nokia.com>
Acked-by: Santosh Shilimkar <Santosh.shilimkar@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index f5c5b8da9a87f194683afa8b51ebecb39e53f302..2c2826571d45856145f7a31a416edee84b13802e 100644 (file)
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -1983,6 +1983,8 @@ static int omap2_dma_handle_ch(int ch)
 
        dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR(ch));
        dma_write(1 << ch, IRQSTATUS_L0);
+       /* read back the register to flush the write */
+       dma_read(IRQSTATUS_L0);
 
        /* If the ch is not chained then chain_id will be -1 */
        if (dma_chan[ch].chain_id != -1) {