interconnect: qcom: rpmh: fix registration race

commit 9937f17535c62ab9eac4a55db0c48c671d7fde51 upstream.

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.

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

Fixes: b43753733b3f ("interconnect: qcom: Consolidate interconnect RPMh support")
Cc: stable@vger.kernel.org      # 5.7
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20230306075651.2449-11-johan+linaro@kernel.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/interconnect/qcom/icc-rpmh.c b/drivers/interconnect/qcom/icc-rpmh.c
index 5168bbf3d92fcefa3ce44e3a98359b0fa4c051e2..fdb5e58e408b4da8d42f614fad20805cc9c09ca0 100644 (file)
--- a/drivers/interconnect/qcom/icc-rpmh.c
+++ b/drivers/interconnect/qcom/icc-rpmh.c
@@ -192,9 +192,10 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
        provider->pre_aggregate = qcom_icc_pre_aggregate;
        provider->aggregate = qcom_icc_aggregate;
        provider->xlate_extended = qcom_icc_xlate_extended;
-       INIT_LIST_HEAD(&provider->nodes);
        provider->data = data;
 
+       icc_provider_init(provider);
+
        qp->dev = dev;
        qp->bcms = desc->bcms;
        qp->num_bcms = desc->num_bcms;
@@ -203,10 +204,6 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
        if (IS_ERR(qp->voter))
                return PTR_ERR(qp->voter);
 
-       ret = icc_provider_add(provider);
-       if (ret)
-               return ret;
-
        for (i = 0; i < qp->num_bcms; i++)
                qcom_icc_bcm_init(qp->bcms[i], dev);
 
@@ -218,7 +215,7 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
                node = icc_node_create(qn->id);
                if (IS_ERR(node)) {
                        ret = PTR_ERR(node);
-                       goto err;
+                       goto err_remove_nodes;
                }
 
                node->name = qn->name;
@@ -232,19 +229,27 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
        }
 
        data->num_nodes = num_nodes;
+
+       ret = icc_provider_register(provider);
+       if (ret)
+               goto err_remove_nodes;
+
        platform_set_drvdata(pdev, qp);
 
        /* Populate child NoC devices if any */
        if (of_get_child_count(dev->of_node) > 0) {
                ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
                if (ret)
-                       goto err;
+                       goto err_deregister_provider;
        }
 
        return 0;
-err:
+
+err_deregister_provider:
+       icc_provider_deregister(provider);
+err_remove_nodes:
        icc_nodes_remove(provider);
-       icc_provider_del(provider);
+
        return ret;
 }
 EXPORT_SYMBOL_GPL(qcom_icc_rpmh_probe);
@@ -253,8 +258,8 @@ int qcom_icc_rpmh_remove(struct platform_device *pdev)
 {
        struct qcom_icc_provider *qp = platform_get_drvdata(pdev);
 
+       icc_provider_deregister(&qp->provider);
        icc_nodes_remove(&qp->provider);
-       icc_provider_del(&qp->provider);
 
        return 0;
 }