[PATCH 6/8] PCI: iproc: fix a leaked reference by adding missing of_node_put

[Wen Yang]

The call to of_parse_phandle returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.
iproc_msi_init also calls of_node_get to increase refcount
(proc_msi_init -> iproc_msi_alloc_domains -> pci_msi_create_irq_domain
-> msi_create_irq_domain -> irq_domain_create_linear -> __irq_domain_add),
so irq_domain will not be affected when it is released.

Detected by coccinelle with the following warnings:
./drivers/pci/controller/pcie-iproc.c:1323:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1299, but without a corresponding object release within this function.
./drivers/pci/controller/pcie-iproc.c:1330:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1299, but without a corresponding object release within this function.

Signed-off-by: Wen Yang <wen.yang99 at zte.com.cn>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
Cc: Bjorn Helgaas <bhelgaas at google.com>
Cc: Ray Jui <rjui at broadcom.com>
Cc: Scott Branden <sbranden at broadcom.com>
Cc: bcm-kernel-feedback-list at broadcom.com
Cc: linux-pci at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-kernel at vger.kernel.org
---
 drivers/pci/controller/pcie-iproc.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pcie-iproc.c b/drivers/pci/controller/pcie-iproc.c
index c20fd6b..9998c5c 100644
--- a/drivers/pci/controller/pcie-iproc.c
+++ b/drivers/pci/controller/pcie-iproc.c
@@ -1320,14 +1320,18 @@ static int iproc_pcie_msi_enable(struct iproc_pcie *pcie)
 	if (pcie->need_msi_steer) {
 		ret = iproc_pcie_msi_steer(pcie, msi_node);
 		if (ret)
-			return ret;
+			goto out_put_node;
 	}
 
 	/*
 	 * If another MSI controller is being used, the call below should fail
 	 * but that is okay
 	 */
-	return iproc_msi_init(pcie, msi_node);
+	ret = iproc_msi_init(pcie, msi_node);
+
+out_put_node:
+	of_node_put(msi_node);
+	return ret;
 }
 
 static void iproc_pcie_msi_disable(struct iproc_pcie *pcie)
-- 
2.9.5