Re: [PATCH 03/36] cpufreq: move to use bus_get_dev_root()

[Rafael J. Wysocki]

On Mon, Mar 13, 2023 at 7:29 PM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> Direct access to the struct bus_type dev_root pointer is going away soon
> so replace that with a call to bus_get_dev_root() instead, which is what
> it is there for.
>
> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> Cc: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> Cc: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
> Cc: Len Brown <lenb@xxxxxxxxxx>
> Cc: linux-pm@xxxxxxxxxxxxxxx
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

> ---
> Note, this is a patch that is a prepatory cleanup as part of a larger
> series of patches that is working on resolving some old driver core
> design mistakes.  It will build and apply cleanly on top of 6.3-rc2 on
> its own, but I'd prefer if I could take it through my driver-core tree
> so that the driver core changes can be taken through there for 6.4-rc1.
>
>  drivers/cpufreq/cpufreq.c      | 7 ++++++-
>  drivers/cpufreq/intel_pstate.c | 7 +++++--
>  2 files changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 6d8fd3b8dcb5..6ad3119b8e15 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -2932,11 +2932,16 @@ EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
>  static int __init cpufreq_core_init(void)
>  {
>         struct cpufreq_governor *gov = cpufreq_default_governor();
> +       struct device *dev_root;
>
>         if (cpufreq_disabled())
>                 return -ENODEV;
>
> -       cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
> +       dev_root = bus_get_dev_root(&cpu_subsys);
> +       if (dev_root) {
> +               cpufreq_global_kobject = kobject_create_and_add("cpufreq", &dev_root->kobj);
> +               put_device(dev_root);
> +       }
>         BUG_ON(!cpufreq_global_kobject);
>
>         if (!strlen(default_governor))
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 48a4613cef1e..102cf7f0ac63 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -1473,10 +1473,13 @@ static struct kobject *intel_pstate_kobject;
>
>  static void __init intel_pstate_sysfs_expose_params(void)
>  {
> +       struct device *dev_root = bus_get_dev_root(&cpu_subsys);
>         int rc;
>
> -       intel_pstate_kobject = kobject_create_and_add("intel_pstate",
> -                                               &cpu_subsys.dev_root->kobj);
> +       if (dev_root) {
> +               intel_pstate_kobject = kobject_create_and_add("intel_pstate", &dev_root->kobj);
> +               put_device(dev_root);
> +       }
>         if (WARN_ON(!intel_pstate_kobject))
>                 return;
>
> --
> 2.39.2
>