dmaengine: fix balance of privatecnt inc/dec operations

This patch increments privatecnt value and set DMA_PRIVATE in device
caps in dma_request_slave_channel() function. This is needed to keep
privatecnt increment/decrement balance.

As function dma_release_channel() decrements privatecnt counter, we need
to increment it when channel is requested. Otherwise privatecnt drops
into negatives after few dma_release_channel() calls.

Reported-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 4a4cce15f25dd65c6a720d949ed0d9c922ff1cba..3ff284c8e3d5aef72f229017c883c73cbe13403f 100644 (file)
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -689,6 +689,10 @@ struct dma_chan *dma_request_slave_channel(struct device *dev,
        struct dma_chan *ch = dma_request_slave_channel_reason(dev, name);
        if (IS_ERR(ch))
                return NULL;
+
+       dma_cap_set(DMA_PRIVATE, ch->device->cap_mask);
+       ch->device->privatecnt++;
+
        return ch;
 }
 EXPORT_SYMBOL_GPL(dma_request_slave_channel);