Re: [PATCH] cpufreq: mediatek: fix device leak on probe failure

Chen-Yu Tsai
2025-09-09T09:57:58Z

On Tue, Sep 9, 2025 at 5:40 PM Johan Hovold <johan@kernel.org> wrote:
>
> Make sure to drop the reference to the cci device taken by
> of_find_device_by_node() on probe failure (e.g. probe deferral).
>
> Fixes: 0daa47325bae ("cpufreq: mediatek: Link CCI device to CPU")
> Cc: Jia-Wei Chang <jia-wei.chang@mediatek.com>
> Cc: Rex-BC Chen <rex-bc.chen@mediatek.com>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
> drivers/cpufreq/mediatek-cpufreq.c | 14 +++++++++++---
> 1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c
> index f3f02c4b6888..21537a05785d 100644
> --- a/drivers/cpufreq/mediatek-cpufreq.c
> +++ b/drivers/cpufreq/mediatek-cpufreq.c
> @@ -404,9 +404,11 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
> }
>
> info->cpu_clk = clk_get(cpu_dev, "cpu");
> - if (IS_ERR(info->cpu_clk))
> - return dev_err_probe(cpu_dev, PTR_ERR(info->cpu_clk),
> - "cpu%d: failed to get cpu clk\n", cpu);
> + if (IS_ERR(info->cpu_clk)) {
> + ret = PTR_ERR(info->cpu_clk);
> + dev_err_probe(cpu_dev, ret, "cpu%d: failed to get cpu clk\n", cpu);
> + goto out_put_cci_dev;
> + }
>
> info->inter_clk = clk_get(cpu_dev, "intermediate");
> if (IS_ERR(info->inter_clk)) {
> @@ -552,6 +554,10 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
> out_free_mux_clock:
> clk_put(info->cpu_clk);
>
> +out_put_cci_dev:
> + if (info->soc_data->ccifreq_supported)
> + put_device(info->cci_dev);

put_device() has a check for NULL, so the if isn't really needed.

Either way,

Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>

> +
> return ret;
> }
>
> @@ -569,6 +575,8 @@ static void mtk_cpu_dvfs_info_release(struct mtk_cpu_dvfs_info *info)
> clk_put(info->inter_clk);
> dev_pm_opp_of_cpumask_remove_table(&info->cpus);
> dev_pm_opp_unregister_notifier(info->cpu_dev, &info->opp_nb);
> + if (info->soc_data->ccifreq_supported)
> + put_device(info->cci_dev);
> }
>
> static int mtk_cpufreq_init(struct cpufreq_policy *policy)
> --
> 2.49.1
>
>