Re: [PATCH 04/23] interconnect: imx: fix registration race

Konrad Dybcio
2023-02-03T02:50:04Z

On 1.02.2023 11:15, Johan Hovold wrote:
> 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: f0d8048525d7 ("interconnect: Add imx core driver")
> Cc: stable@vger.kernel.org # 5.8
> Cc: Leonard Crestez <leonard.crestez@nxp.com>
> Cc: Alexandre Bailon <abailon@baylibre.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
> drivers/interconnect/imx/imx.c | 20 ++++++++++----------
> 1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/interconnect/imx/imx.c b/drivers/interconnect/imx/imx.c
> index 823d9be9771a..979ed610f704 100644
> --- 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);
>