Re: [RFC PATCH] PM / Domains: Ensure subdomain is not in use before removing

[Kevin Hilman <khilman@kernel.org>]

Jon Hunter <jonathanh@nvidia.com> writes:

> The function pm_genpd_remove_subdomain() removes a subdomain from a
> generic PM domain, however, it does not check if the subdomain has any
> slave domains or device attached before doing so. Therefore, add a test
> to verify that the subdomain does not have any slave domains associated
> or any device attached before removing.
>
> Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
> ---
>  drivers/base/power/domain.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 27888a90ca98..a3ed71d8129a 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -1469,6 +1469,11 @@ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
>  
>  	mutex_lock(&genpd->lock);
>  
> +	if (!list_empty(&subdomain->slave_links) || subdomain->device_count) {

maybe a pr_warn() or similar is appropriate here?

> +		ret = -EBUSY;
> +		goto out;
> +	}
> +

... otherwise looks like a good check to add.

Acked-by: Kevin Hilman <khilman@linaro.org>