[PATCH 5.8 039/186] dmaengine: of-dma: Fix of_dma_router_xlates of_dma_xlate handling

[Greg Kroah-Hartman]

From: Peter Ujfalusi <peter.ujfalusi@xxxxxx>

[ Upstream commit 5b2aa9f918f6837ae943557f8cec02c34fcf80e7 ]

of_dma_xlate callback can return ERR_PTR as well NULL in case of failure.

If error code is returned (not NULL) then the route should be released and
the router should not be registered for the channel.

Fixes: 56f13c0d9524c ("dmaengine: of_dma: Support for DMA routers")
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
Link: https://lore.kernel.org/r/20200806104928.25975-1-peter.ujfalusi@xxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/dma/of-dma.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c
index b2c2b5e8093cf..0db816eb8080d 100644
--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -71,12 +71,12 @@ static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec,
 		return NULL;
 
 	chan = ofdma_target->of_dma_xlate(&dma_spec_target, ofdma_target);
-	if (chan) {
-		chan->router = ofdma->dma_router;
-		chan->route_data = route_data;
-	} else {
+	if (IS_ERR_OR_NULL(chan)) {
 		ofdma->dma_router->route_free(ofdma->dma_router->dev,
 					      route_data);
+	} else {
+		chan->router = ofdma->dma_router;
+		chan->route_data = route_data;
 	}
 
 	/*
-- 
2.25.1