Re: [PATCH] drm: rcar-du: Fix the return check of of_parse_phandle and of_find_device_by_node

Hi Wang Xiaojun,

On 11/11/2020 03:14, Wang Xiaojun wrote:

of_parse_phandle and of_find_device_by_node may return NULL which cannot be checked by IS_ERR.

Indeed, both of these functions return either NULL or the correct value, and no an errno.

Signed-off-by: Wang Xiaojun wangxiaojun11@huawei.com Reported-by: Hulk Robot hulkci@huawei.com

Fixes: 8de707aeb452 ("drm: rcar-du: kms: Initialize CMM instances")

Reviewed-by: Kieran Bingham kieran.bingham+renesas@ideasonboard.com

---

drivers/gpu/drm/rcar-du/rcar_du_kms.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c index 72dda446355f..fcfddf7ad3f3 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c @@ -700,10 +700,10 @@ static int rcar_du_cmm_init(struct rcar_du_device *rcdu) int ret;

cmm = of_parse_phandle(np, "renesas,cmms", i);

• if (IS_ERR(cmm)) {
  

• if (!cmm) {
  dev_err(rcdu->dev,
  	"Failed to parse 'renesas,cmms' property\n");
  

• 	return PTR_ERR(cmm);
  

• 	return -ENODEV;
  

  }

  if (!of_device_is_available(cmm)) {

@@ -713,10 +713,10 @@ static int rcar_du_cmm_init(struct rcar_du_device *rcdu) }

pdev = of_find_device_by_node(cmm);

• if (IS_ERR(pdev)) {
  

• if (!pdev) {
  dev_err(rcdu->dev, "No device found for CMM%u\n", i);
  of_node_put(cmm);
  

• 	return PTR_ERR(pdev);
  

• 	return -ENODEV;
  

  }

  of_node_put(cmm);