Patch "interconnect: qcom: rpmh: fix registration race" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    interconnect: qcom: rpmh: fix registration race

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     interconnect-qcom-rpmh-fix-registration-race.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit f2af30bfe98d839c192d36dfbebde92e99e297ed
Author: Johan Hovold <johan+linaro@xxxxxxxxxx>
Date:   Mon Mar 6 08:56:38 2023 +0100

    interconnect: qcom: rpmh: fix registration race
    
    [ Upstream commit 74240a5bebd48d8b843c6d0f1acfaa722a5abeb7 ]
    
    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: 976daac4a1c5 ("interconnect: qcom: Consolidate interconnect RPMh support")
    Cc: stable@xxxxxxxxxxxxxxx      # 5.7
    Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
    Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20230306075651.2449-11-johan+linaro@xxxxxxxxxx
    Signed-off-by: Georgi Djakov <djakov@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/interconnect/qcom/icc-rpmh.c b/drivers/interconnect/qcom/icc-rpmh.c
index 2c8e12549804b..c51c39754f4b1 100644
--- a/drivers/interconnect/qcom/icc-rpmh.c
+++ b/drivers/interconnect/qcom/icc-rpmh.c
@@ -216,9 +216,10 @@ 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;
@@ -227,10 +228,6 @@ 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);
 
@@ -242,7 +239,7 @@ 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;
@@ -256,12 +253,18 @@ 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);
 
 	return 0;
-err:
+
+err_remove_nodes:
 	icc_nodes_remove(provider);
-	icc_provider_del(provider);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(qcom_icc_rpmh_probe);
@@ -270,8 +273,10 @@ 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);
-	return icc_provider_del(&qp->provider);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(qcom_icc_rpmh_remove);