[PATCH 05/23] interconnect: qcom: osm-l3: fix registration race

Johan Hovold posted 23 patches 2 years, 7 months ago
There is a newer version of this series
[PATCH 05/23] interconnect: qcom: osm-l3: fix registration race
Posted by Johan Hovold 2 years, 7 months ago
The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail:

	of_icc_xlate_onecell: invalid index 0
	cpu cpu0: error -EINVAL: error finding src node
	cpu cpu0: dev_pm_opp_of_find_icc_paths: Unable to get path0: -22
	qcom-cpufreq-hw: probe of 18591000.cpufreq failed with error -22

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: 5bc9900addaf ("interconnect: qcom: Add OSM L3 interconnect provider support")
Cc: stable@vger.kernel.org      # 5.7
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/qcom/osm-l3.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/interconnect/qcom/osm-l3.c b/drivers/interconnect/qcom/osm-l3.c
index 5fa171087425..3a1cbfe3e481 100644
--- a/drivers/interconnect/qcom/osm-l3.c
+++ b/drivers/interconnect/qcom/osm-l3.c
@@ -158,8 +158,8 @@ static int qcom_osm_l3_remove(struct platform_device *pdev)
 {
 	struct qcom_osm_l3_icc_provider *qp = platform_get_drvdata(pdev);
 
+	icc_provider_deregister(&qp->provider);
 	icc_nodes_remove(&qp->provider);
-	icc_provider_del(&qp->provider);
 
 	return 0;
 }
@@ -245,14 +245,9 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
 	provider->set = qcom_osm_l3_set;
 	provider->aggregate = icc_std_aggregate;
 	provider->xlate = of_icc_xlate_onecell;
-	INIT_LIST_HEAD(&provider->nodes);
 	provider->data = data;
 
-	ret = icc_provider_add(provider);
-	if (ret) {
-		dev_err(&pdev->dev, "error adding interconnect provider\n");
-		return ret;
-	}
+	icc_provider_init(provider);
 
 	for (i = 0; i < num_nodes; i++) {
 		size_t j;
@@ -275,12 +270,15 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
 	}
 	data->num_nodes = num_nodes;
 
+	ret = icc_provider_register(provider);
+	if (ret)
+		goto err;
+
 	platform_set_drvdata(pdev, qp);
 
 	return 0;
 err:
 	icc_nodes_remove(provider);
-	icc_provider_del(provider);
 
 	return ret;
 }
-- 
2.39.1
Re: [PATCH 05/23] interconnect: qcom: osm-l3: fix registration race
Posted by Konrad Dybcio 2 years, 7 months ago

On 1.02.2023 11:15, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail:
> 
> 	of_icc_xlate_onecell: invalid index 0
> 	cpu cpu0: error -EINVAL: error finding src node
> 	cpu cpu0: dev_pm_opp_of_find_icc_paths: Unable to get path0: -22
> 	qcom-cpufreq-hw: probe of 18591000.cpufreq failed with error -22
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: 5bc9900addaf ("interconnect: qcom: Add OSM L3 interconnect provider support")
> Cc: stable@vger.kernel.org      # 5.7
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/qcom/osm-l3.c | 14 ++++++--------
>  1 file changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/osm-l3.c b/drivers/interconnect/qcom/osm-l3.c
> index 5fa171087425..3a1cbfe3e481 100644
> --- a/drivers/interconnect/qcom/osm-l3.c
> +++ b/drivers/interconnect/qcom/osm-l3.c
> @@ -158,8 +158,8 @@ static int qcom_osm_l3_remove(struct platform_device *pdev)
>  {
>  	struct qcom_osm_l3_icc_provider *qp = platform_get_drvdata(pdev);
>  
> +	icc_provider_deregister(&qp->provider);
>  	icc_nodes_remove(&qp->provider);
> -	icc_provider_del(&qp->provider);
>  
>  	return 0;
>  }
> @@ -245,14 +245,9 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
>  	provider->set = qcom_osm_l3_set;
>  	provider->aggregate = icc_std_aggregate;
>  	provider->xlate = of_icc_xlate_onecell;
> -	INIT_LIST_HEAD(&provider->nodes);
>  	provider->data = data;
>  
> -	ret = icc_provider_add(provider);
> -	if (ret) {
> -		dev_err(&pdev->dev, "error adding interconnect provider\n");
> -		return ret;
> -	}
> +	icc_provider_init(provider);
>  
>  	for (i = 0; i < num_nodes; i++) {
>  		size_t j;
> @@ -275,12 +270,15 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
>  	}
>  	data->num_nodes = num_nodes;
>  
> +	ret = icc_provider_register(provider);
> +	if (ret)
> +		goto err;
> +
>  	platform_set_drvdata(pdev, qp);
>  
>  	return 0;
>  err:
>  	icc_nodes_remove(provider);
> -	icc_provider_del(provider);
>  
>  	return ret;
>  }