Re: [PATCH 13/23] interconnect: qcom: sm8550: fix registration race

Abel Vesa
2023-02-01T10:21:53Z

On 23-02-01 11:15:49, 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.

Sounds good to me.

>
> Fixes: e6f0d6a30f73 ("interconnect: qcom: Add SM8550 interconnect provider driver")
> Cc: Abel Vesa <abel.vesa@linaro.org>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>

Reviewed-by: Abel Vesa <abel.vesa@linaro.org>

> ---
> drivers/interconnect/qcom/sm8550.c | 22 +++++++++++-----------
> 1 file changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/interconnect/qcom/sm8550.c b/drivers/interconnect/qcom/sm8550.c
> index 54fa027ab961..7ab492ca8fe0 100644
> --- a/drivers/interconnect/qcom/sm8550.c
> +++ b/drivers/interconnect/qcom/sm8550.c
> @@ -2197,9 +2197,10 @@ static int qnoc_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 = &pdev->dev;
> qp->bcms = desc->bcms;
> qp->num_bcms = desc->num_bcms;
> @@ -2208,12 +2209,6 @@ static int qnoc_probe(struct platform_device *pdev)
> if (IS_ERR(qp->voter))
> return PTR_ERR(qp->voter);
>
> - ret = icc_provider_add(provider);
> - if (ret) {
> - dev_err_probe(&pdev->dev, ret,
> - "error adding interconnect provider\n");
> - return ret;
> - }
>
> for (i = 0; i < qp->num_bcms; i++)
> qcom_icc_bcm_init(qp->bcms[i], &pdev->dev);
> @@ -2227,7 +2222,7 @@ static int qnoc_probe(struct platform_device *pdev)
> node = icc_node_create(qnodes[i]->id);
> if (IS_ERR(node)) {
> ret = PTR_ERR(node);
> - goto err;
> + goto err_remove_nodes;
> }
>
> node->name = qnodes[i]->name;
> @@ -2241,12 +2236,17 @@ static int qnoc_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;
> }
>
> @@ -2254,8 +2254,8 @@ static int qnoc_remove(struct platform_device *pdev)
> {
> struct qcom_icc_provider *qp = platform_get_drvdata(pdev);
>
> + icc_provider_deregister(&qp->provider);
> icc_nodes_remove(&qp->provider);
> - icc_provider_del(&qp->provider);
>
> return 0;
> }
> --
> 2.39.1
>