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>
torvalds · Aug 17, 2015 · 05aa1a7 · 05aa1a7
1 parent 2c6625c
commit 05aa1a7
Showing 1 changed file with 4 additions and 0 deletions.
diff --git 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);