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>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 4a4cce15f25d..3ff284c8e3d5 100644
--- 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);