[PATCH] drm/rockchip: dsi: Fix second reference leak in dw_mipi_dsi_rockchip_bind()

[Wentao Liang]

dw_mipi_dsi_rockchip_find_second() hands back the dual-DSI partner
device with a reference from of_find_device_by_node().  The bind path
only drops it after a successful master setup; the four early returns
(both/no clock-master, the slave shortcut and a missing slave drvdata)
leave the reference behind.  Drop it on all of them.

Fixes: cf6d100dd238 ("drm/rockchip: dsi: add dual mipi support")
Cc: stable at vger.kernel.org
Signed-off-by: Wentao Liang <vulab at iscas.ac.cn>
---
 drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
index 3547d91b25d3..4ab29410b2c0 100644
--- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
@@ -933,23 +933,27 @@ static int dw_mipi_dsi_rockchip_bind(struct device *dev,
 
 		if (master1 && master2) {
 			DRM_DEV_ERROR(dsi->dev, "only one clock-master allowed\n");
+			put_device(second);
 			return -EINVAL;
 		}
 
 		if (!master1 && !master2) {
 			DRM_DEV_ERROR(dsi->dev, "no clock-master defined\n");
+			put_device(second);
 			return -EINVAL;
 		}
 
 		/* we are the slave in dual-DSI */
 		if (!master1) {
 			dsi->is_slave = true;
+			put_device(second);
 			return 0;
 		}
 
 		dsi->slave = dev_get_drvdata(second);
 		if (!dsi->slave) {
 			DRM_DEV_ERROR(dev, "could not get slaves data\n");
+			put_device(second);
 			return -ENODEV;
 		}
 
-- 
2.34.1