linux-kernel - Re: [PATCH v3] PM / suspend: Export pm_suspend_target

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Message-ID: <3384121.PEd7U8K5ps@aspire.rjw.lan>
Date:   Tue, 18 Jul 2017 01:24:54 +0200
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Florian Fainelli <f.fainelli@...il.com>
Cc:     linux-kernel@...r.kernel.org,
        Alexandre Belloni <alexandre.belloni@...e-electrons.com>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        linux-pm <linux-pm@...r.kernel.org>,
        Thibaud Cornic <thibaud_cornic@...madesigns.com>,
        JB <jb_lescher@...madesigns.com>, Mason <slash.tmp@...e.fr>,
        Kevin Hilman <khilman@...nel.org>, Pavel Machek <pavel@....cz>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v3] PM / suspend: Export pm_suspend_target_state

On Monday, July 17, 2017 03:10:59 PM Florian Fainelli wrote:
> Have the core suspend/resume framework store the system-wide suspend
> state (suspend_state_t) we are about to enter, and expose it to drivers
> via pm_suspend_target_state in order to retrieve that. The state is
> assigned in suspend_devices_and_enter().
> 
> This is useful for platform specific drivers that may need to take a
> slightly different suspend/resume path based on the system's
> suspend/resume state being entered.
> 
> Signed-off-by: Florian Fainelli <f.fainelli@...il.com>
> ---
> Changes in v3:
> 
> - just export pm_suspend_target_state without a helper function
> 
> Changes in v2:
> 
> - rename platform_suspend_target_state() -> suspend_target_state()
> - directly export the suspend_state_t value and assign it in
>   suspend_devices_and_enter()
> 
>  include/linux/suspend.h | 1 +
>  kernel/power/suspend.c  | 4 ++++
>  2 files changed, 5 insertions(+)
> 
> diff --git a/include/linux/suspend.h b/include/linux/suspend.h
> index 0b1cf32edfd7..2159f6841768 100644
> --- a/include/linux/suspend.h
> +++ b/include/linux/suspend.h
> @@ -427,6 +427,7 @@ extern int unregister_pm_notifier(struct notifier_block *nb);
>  /* drivers/base/power/wakeup.c */
>  extern bool events_check_enabled;
>  extern unsigned int pm_wakeup_irq;
> +extern suspend_state_t pm_suspend_target_state;
>  
>  extern bool pm_wakeup_pending(void);
>  extern void pm_system_wakeup(void);
> diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
> index 3ecf275d7e44..1aecdaf22ab5 100644
> --- a/kernel/power/suspend.c
> +++ b/kernel/power/suspend.c
> @@ -47,6 +47,8 @@ const char *mem_sleep_states[PM_SUSPEND_MAX];
>  
>  suspend_state_t mem_sleep_current = PM_SUSPEND_FREEZE;
>  static suspend_state_t mem_sleep_default = PM_SUSPEND_MEM;
> +suspend_state_t pm_suspend_target_state;
> +EXPORT_SYMBOL_GPL(pm_suspend_target_state);
>  
>  unsigned int pm_suspend_global_flags;
>  EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
> @@ -456,6 +458,8 @@ int suspend_devices_and_enter(suspend_state_t state)
>  	if (!sleep_state_supported(state))
>  		return -ENOSYS;
>  
> +	pm_suspend_target_state = state;
> +
>  	error = platform_suspend_begin(state);
>  	if (error)
>  		goto Close;
> 

And please clear pm_suspend_target_state before returning from
suspend_devices_and_enter().

Thanks,
Rafael