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

From: Sudeep Holla
Date: Fri Oct 12 2018 - 10:25:12 EST


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