Re: [PATCH RFC v1 7/8] drivers: qcom: cpu_pd: Handle cpu hotplug in the domain

[Sudeep Holla]

On Thu, Oct 11, 2018 at 02:50:54AM +0530, Raju P.L.S.S.S.N wrote:
> Use cpu hotplug callback mechanism to attach/dettach the cpu in
> the cpu power domain. During cpu hotplug callback registration,
> the starting callback is invoked on all online cpus. So there is
> no need to attach from device probe.
> 
> Signed-off-by: Raju P.L.S.S.S.N <rplsssn@xxxxxxxxxxxxxx>
> ---
>  drivers/soc/qcom/cpu_pd.c  | 33 +++++++++++++++++++++++++--------
>  include/linux/cpuhotplug.h |  1 +
>  2 files changed, 26 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/soc/qcom/cpu_pd.c b/drivers/soc/qcom/cpu_pd.c
> index 242eced..bf2d95d 100644
> --- a/drivers/soc/qcom/cpu_pd.c
> +++ b/drivers/soc/qcom/cpu_pd.c
> @@ -3,6 +3,7 @@
>   * Copyright (c) 2018, The Linux Foundation. All rights reserved.
>   */
>  
> +#include <linux/cpuhotplug.h>
>  #include <linux/ktime.h>
>  #include <linux/of_platform.h>
>  #include <linux/pm_domain.h>
> @@ -85,12 +86,26 @@ static int cpu_pd_power_off(struct generic_pm_domain *domain)
>  	return 0;
>  }
>  
> +static int cpu_pd_starting(unsigned int cpu)
> +{
> +	if (!suspend && of_genpd_attach_cpu(cpu))
> +		pr_err("%s: genpd_attach_cpu fail\n", __func__);

If it's that serious, return proper error code and drop the message which
could be annoying if you are running some hotplug test loop.

--
Regards,
Sudeep