[PATCH] soc: qcom: smsm: fix child-node lookup

[PATCH] soc: qcom: smsm: fix child-node lookup

[Johan Hovold]

Fix child-node lookup during probe, which ended up searching the whole
device tree depth-first starting at the parent rather than just matching
on its children.

Note that the original premature free of the parent node has already
been fixed separately.

Also note that this pattern of looking up the first child node with a
given property is rare enough that a generic helper is probably not
warranted.

Fixes: c97c4090ff72 ("soc: qcom: smsm: Add driver for Qualcomm SMSM")
Fixes: 3e8b55411468 ("soc: qcom: smsm: fix of_node refcnting problem")
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Rob Clark <robdclark@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/soc/qcom/smsm.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/qcom/smsm.c b/drivers/soc/qcom/smsm.c
index 403bea9d546b..50214b620865 100644
--- a/drivers/soc/qcom/smsm.c
+++ b/drivers/soc/qcom/smsm.c
@@ -496,8 +496,10 @@ static int qcom_smsm_probe(struct platform_device *pdev)
 	if (!smsm->hosts)
 		return -ENOMEM;
 
-	local_node = of_find_node_with_property(of_node_get(pdev->dev.of_node),
-						"#qcom,smem-state-cells");
+	for_each_child_of_node(pdev->dev.of_node, local_node) {
+		if (of_find_property(local_node, "#qcom,smem-state-cells", NULL))
+			break;
+	}
 	if (!local_node) {
 		dev_err(&pdev->dev, "no state entry\n");
 		return -EINVAL;
-- 
2.15.0

Re: [PATCH] soc: qcom: smsm: fix child-node lookup

[Bjorn Andersson]

On Wed 15 Nov 03:07 PST 2017, Johan Hovold wrote:

> Fix child-node lookup during probe, which ended up searching the whole
> device tree depth-first starting at the parent rather than just matching
> on its children.
> 
> Note that the original premature free of the parent node has already
> been fixed separately.
> 
> Also note that this pattern of looking up the first child node with a
> given property is rare enough that a generic helper is probably not
> warranted.
> 

I agree.

> Fixes: c97c4090ff72 ("soc: qcom: smsm: Add driver for Qualcomm SMSM")
> Fixes: 3e8b55411468 ("soc: qcom: smsm: fix of_node refcnting problem")
> Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
> Cc: Rob Clark <robdclark@gmail.com>
> Signed-off-by: Johan Hovold <johan@kernel.org>

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Thanks,
Bjorn

> ---
>  drivers/soc/qcom/smsm.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/soc/qcom/smsm.c b/drivers/soc/qcom/smsm.c
> index 403bea9d546b..50214b620865 100644
> --- a/drivers/soc/qcom/smsm.c
> +++ b/drivers/soc/qcom/smsm.c
> @@ -496,8 +496,10 @@ static int qcom_smsm_probe(struct platform_device *pdev)
>  	if (!smsm->hosts)
>  		return -ENOMEM;
>  
> -	local_node = of_find_node_with_property(of_node_get(pdev->dev.of_node),
> -						"#qcom,smem-state-cells");
> +	for_each_child_of_node(pdev->dev.of_node, local_node) {
> +		if (of_find_property(local_node, "#qcom,smem-state-cells", NULL))
> +			break;
> +	}
>  	if (!local_node) {
>  		dev_err(&pdev->dev, "no state entry\n");
>  		return -EINVAL;
> -- 
> 2.15.0
>