interconnect: qcom: osm-l3: fix registration race

commit 3d0bce266fcea3fcd2ce265a68e44a000af3577f 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:

	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: 0a20ef8382a0 ("interconnect: qcom: Add OSM L3 interconnect provider 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/20230306075651.2449-6-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/osm-l3.c b/drivers/interconnect/qcom/osm-l3.c
index ddbdf0943f94e7181deb7af0a41d36690a8d9439..333adb21e717607fe4a799d2063a0505afeb3ca0 100644 (file)
--- a/drivers/interconnect/qcom/osm-l3.c
+++ b/drivers/interconnect/qcom/osm-l3.c
@@ -216,8 +216,8 @@ 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;
 }
@@ -303,14 +303,9 @@ 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;
@@ -333,12 +328,15 @@ 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;
 }