[PATCH v2 05/23] interconnect: qcom: osm-l3: fix registration race

[Johan Hovold]

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 at vger.kernel.org      # 5.7
Reviewed-by: Konrad Dybcio <konrad.dybcio at linaro.org>
Signed-off-by: Johan Hovold <johan+linaro at 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;
 }
-- 
2.39.2