> -----Original Message-----
> From: linux-omap-ow...@vger.kernel.org [mailto:linux-omap-
> ow...@vger.kernel.org] On Behalf Of Mathias Nyman
> Sent: Monday, October 25, 2010 8:05 PM
> To: linux-omap@vger.kernel.org
> Cc: Mathias Nyman
> Subject: [PATCH] omap: dma: Add read-back to DMA interrupt handler to
> avoid spurious interrupts
>
> 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
>
Good fix Mathias.
Actually we should also clear other status lines as well when
used with multiple master initiator scenario's. But that need some
additional fixes as well.
> Signed-off-by: Mathias Nyman <mathias.ny...@nokia.com>
Acked-by: Santosh Shilimkar <santosh.shilim...@ti.com>
> ---
> arch/arm/plat-omap/dma.c | 2 ++
> 1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
> index f5c5b8d..2c28265 100644
> --- 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) {
> --
> 1.5.6.5
>
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