interconnect: qcom: msm8974: fix registration race

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: 4e60a9568dc6 ("interconnect: qcom: add msm8974 driver")
Cc: stable@vger.kernel.org      # 5.5
Reviewed-by: Brian Masney <bmasney@redhat.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20230306075651.2449-12-johan+linaro@kernel.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>

diff --git a/drivers/interconnect/qcom/msm8974.c b/drivers/interconnect/qcom/msm8974.c
index 5ea192f..1828dea 100644 (file)
--- a/drivers/interconnect/qcom/msm8974.c
+++ b/drivers/interconnect/qcom/msm8974.c
@@ -692,7 +692,6 @@ static int msm8974_icc_probe(struct platform_device *pdev)
                return ret;
 
        provider = &qp->provider;
-       INIT_LIST_HEAD(&provider->nodes);
        provider->dev = dev;
        provider->set = msm8974_icc_set;
        provider->aggregate = icc_std_aggregate;
@@ -700,11 +699,7 @@ static int msm8974_icc_probe(struct platform_device *pdev)
        provider->data = data;
        provider->get_bw = msm8974_get_bw;
 
-       ret = icc_provider_add(provider);
-       if (ret) {
-               dev_err(dev, "error adding interconnect provider: %d\n", ret);
-               goto err_disable_clks;
-       }
+       icc_provider_init(provider);
 
        for (i = 0; i < num_nodes; i++) {
                size_t j;
@@ -712,7 +707,7 @@ static int msm8974_icc_probe(struct platform_device *pdev)
                node = icc_node_create(qnodes[i]->id);
                if (IS_ERR(node)) {
                        ret = PTR_ERR(node);
-                       goto err_del_icc;
+                       goto err_remove_nodes;
                }
 
                node->name = qnodes[i]->name;
@@ -729,15 +724,16 @@ static int msm8974_icc_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);
 
        return 0;
 
-err_del_icc:
+err_remove_nodes:
        icc_nodes_remove(provider);
-       icc_provider_del(provider);
-
-err_disable_clks:
        clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
 
        return ret;
@@ -747,9 +743,9 @@ static int msm8974_icc_remove(struct platform_device *pdev)
 {
        struct msm8974_icc_provider *qp = platform_get_drvdata(pdev);
 
+       icc_provider_deregister(&qp->provider);
        icc_nodes_remove(&qp->provider);
        clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
-       icc_provider_del(&qp->provider);
 
        return 0;
 }