Messages in this thread | | | Date | Thu, 15 Oct 2009 18:25:14 -0700 | Subject | Re: [PATCH v0 1/2] DMA: fsldma: Disable DMA_INTERRUPT when Async_tx enabled | From | Dan Williams <> |
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[ added Leo and Timur to the Cc ]
On Wed, Oct 14, 2009 at 11:41 PM, Vishnu Suresh <Vishnu@freescale.com> wrote: > This patch disables the use of DMA_INTERRUPT capability with Async_tx > > The fsldma produces a null transfer with DMA_INTERRUPT > capability when used with Async_tx. When RAID devices queue > a transaction via Async_tx, this results in a hang. > > Signed-off-by: Vishnu Suresh <Vishnu@freescale.com> > --- > drivers/dma/fsldma.c | 6 ++++++ > 1 files changed, 6 insertions(+), 0 deletions(-) > > diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c > index 296f9e7..66d9b39 100644 > --- a/drivers/dma/fsldma.c > +++ b/drivers/dma/fsldma.c > @@ -1200,7 +1200,13 @@ static int __devinit of_fsl_dma_probe(struct of_device *dev, > - fdev->reg.start + 1); > > dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask); > +#ifndef CONFIG_ASYNC_CORE > + /* > + * The DMA_INTERRUPT async_tx is a NULL transfer, which will > + * triger a PE interrupt. > + */ > dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask); > +#endif > dma_cap_set(DMA_SLAVE, fdev->common.cap_mask); > fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources; > fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
You are basically saying that fsl_dma_prep_interrupt() is buggy. Can that routine be fixed rather than this piecemeal solution? If it cannot be fixed (i.e. hardware issue) then fsl_dma_prep_interrupt() should just be disabled/deleted altogether.
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