[PATCH v0 1/2] DMA: fsldma: Disable DMA_INTERRUPT when Async_tx enabled

From: Vishnu Suresh
Date: Thu Oct 15 2009 - 02:50:54 EST


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@xxxxxxxxxxxxx>
---
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;
--
1.6.4.2

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