interconnect: imx: fix registration race

commit 3b4c0480dfc879ff3a6f6037445a8a967b3e3dde 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: b6d08f322657 ("interconnect: Add imx core driver")
Cc: stable@vger.kernel.org      # 5.8
Cc: Alexandre Bailon <abailon@baylibre.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # i.MX8MP MSC SM2-MB-EP1 Board
Link: https://lore.kernel.org/r/20230306075651.2449-5-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/imx/imx.c b/drivers/interconnect/imx/imx.c
index 823d9be9771a1c70a3d3db7d3b844a68c868854c..979ed610f704b576d346547deba78a2ea2b2a4d5 100644 (file)
--- a/drivers/interconnect/imx/imx.c
+++ b/drivers/interconnect/imx/imx.c
@@ -295,6 +295,9 @@ int imx_icc_register(struct platform_device *pdev,
        provider->xlate = of_icc_xlate_onecell;
        provider->data = data;
        provider->dev = dev->parent;
+
+       icc_provider_init(provider);
+
        platform_set_drvdata(pdev, imx_provider);
 
        if (settings) {
@@ -306,20 +309,18 @@ int imx_icc_register(struct platform_device *pdev,
                }
        }
 
-       ret = icc_provider_add(provider);
-       if (ret) {
-               dev_err(dev, "error adding interconnect provider: %d\n", ret);
+       ret = imx_icc_register_nodes(imx_provider, nodes, nodes_count, settings);
+       if (ret)
                return ret;
-       }
 
-       ret = imx_icc_register_nodes(imx_provider, nodes, nodes_count, settings);
+       ret = icc_provider_register(provider);
        if (ret)
-               goto provider_del;
+               goto err_unregister_nodes;
 
        return 0;
 
-provider_del:
-       icc_provider_del(provider);
+err_unregister_nodes:
+       imx_icc_unregister_nodes(&imx_provider->provider);
        return ret;
 }
 EXPORT_SYMBOL_GPL(imx_icc_register);
@@ -328,9 +329,8 @@ void imx_icc_unregister(struct platform_device *pdev)
 {
        struct imx_icc_provider *imx_provider = platform_get_drvdata(pdev);
 
+       icc_provider_deregister(&imx_provider->provider);
        imx_icc_unregister_nodes(&imx_provider->provider);
-
-       icc_provider_del(&imx_provider->provider);
 }
 EXPORT_SYMBOL_GPL(imx_icc_unregister);