[PATCH 4.18 068/158] gpu: ipu-v3: default to id 0 on missing OF alias

[Greg Kroah-Hartman]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>

[ Upstream commit 2d87e6c1b99c402360fdfe19ce4f579ab2f96adf ]

This is better than storing -ENODEV in the id number. This fixes SoCs
with only one IPU that don't specify an IPU alias in the device tree.

Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpu/ipu-v3/ipu-common.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/gpu/ipu-v3/ipu-common.c
+++ b/drivers/gpu/ipu-v3/ipu-common.c
@@ -1401,6 +1401,8 @@ static int ipu_probe(struct platform_dev
 		return -ENODEV;
 
 	ipu->id = of_alias_get_id(np, "ipu");
+	if (ipu->id < 0)
+		ipu->id = 0;
 
 	if (of_device_is_compatible(np, "fsl,imx6qp-ipu") &&
 	    IS_ENABLED(CONFIG_DRM)) {