[PATCH v2 1/3] dma: mxs-dma: Cleanup interrupt handler

[Markus Pargmann]

Hi,

On Mon, Sep 30, 2013 at 03:59:10PM +0200, Marc Kleine-Budde wrote:
> On 09/30/2013 03:54 PM, Lothar Waßmann wrote:
> > Hi,
> > 
> > Markus Pargmann writes:
> >> The DMA interrupt handler uses its controll registers to handle all
> >> available channel interrupts it can find.
> >>
> >> This patch changes it to handle only one interrupt by directly mapping
> >> irq number to channel. It also includes a cleanup of the ctrl-register
> >> usage.
> >>
> >> Signed-off-by: Markus Pargmann <mpa at pengutronix.de>
> >> ---
> >>  drivers/dma/mxs-dma.c | 95 ++++++++++++++++++++++++++++++++-------------------
> >>  1 file changed, 59 insertions(+), 36 deletions(-)
> >>
> >> diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
> >> index ccd13df..bfca8dc 100644
> >> --- a/drivers/dma/mxs-dma.c
> >> +++ b/drivers/dma/mxs-dma.c
> >> @@ -272,58 +272,81 @@ static void mxs_dma_tasklet(unsigned long data)
> >>  		mxs_chan->desc.callback(mxs_chan->desc.callback_param);
> >>  }
> >>  
> >> +static int mxs_dma_irq_to_chan(struct mxs_dma_engine *mxs_dma, int irq)
> >> +{
> >> +	int i;
> >> +
> >> +	for (i = 0; i != mxs_dma->nr_channels; ++i)
> >> +		if (mxs_dma->mxs_chans[i].chan_irq == irq)
> >> +			return i;
> >>
> > You might use a linked list for all active channels so that you don't
> > have to check all unused channels when trying to find the channel
> > number for an irq.
> 
> Or an array of mxs_dma->nr_channels length for direct mapping.

We map irq to channel so an array of nr_channels won't work here.

I will use a linked list.

Thanks

Markus


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