[PATCH] drm: rcar-du: Fix leak of CMM platform device reference

[Laurent Pinchart]

The device references acquired by of_find_device_by_node() are not
released by the driver. Fix this by registering a cleanup action.

Fixes: 8de707aeb452 ("drm: rcar-du: kms: Initialize CMM instances")
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>
---
 drivers/gpu/drm/rcar-du/rcar_du_kms.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
index 92dfa3d4c011..7070f3c9b529 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
@@ -14,6 +14,7 @@
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_managed.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_vblank.h>
 
@@ -721,6 +722,8 @@ static int rcar_du_cmm_init(struct rcar_du_device *rcdu)
 
 		of_node_put(cmm);
 
+		rcdu->cmms[i] = pdev;
+
 		/*
 		 * -ENODEV is used to report that the CMM config option is
 		 * disabled: return 0 and let the DU continue probing.
@@ -739,13 +742,22 @@ static int rcar_du_cmm_init(struct rcar_du_device *rcdu)
 				"Failed to create device link to CMM%u\n", i);
 			return -EINVAL;
 		}
-
-		rcdu->cmms[i] = pdev;
 	}
 
 	return 0;
 }
 
+static void rcar_du_modeset_cleanup(struct drm_device *dev, void *res)
+{
+	struct rcar_du_device *rcdu = to_rcar_du_device(dev);
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(rcdu->cmms); ++i) {
+		if (rcdu->cmms[i])
+			put_device(&rcdu->cmms[i]->dev);
+	}
+}
+
 int rcar_du_modeset_init(struct rcar_du_device *rcdu)
 {
 	static const unsigned int mmio_offsets[] = {
@@ -766,6 +778,10 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu)
 	if (ret)
 		return ret;
 
+	ret = drmm_add_action(&rcdu->ddev, rcar_du_modeset_cleanup, NULL);
+	if (ret)
+		return ret;
+
 	dev->mode_config.min_width = 0;
 	dev->mode_config.min_height = 0;
 	dev->mode_config.normalize_zpos = true;
-- 
Regards,

Laurent Pinchart