Re: [PATCH 3/4][RFC v2] PM / hibernate: introduce a flag to indicate resuming from hibernation

From: Pavel Machek
Date: Sat Jun 25 2016 - 12:53:10 EST


On Sun 2016-06-26 00:18:52, Chen Yu wrote:
> Sometime we need to do some operations before resuming from
> hibernation, so introduce a flag to indicate this stage.
>
> Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
> ---
> include/linux/suspend.h | 7 +++++++
> kernel/power/hibernate.c | 3 +++
> 2 files changed, 10 insertions(+)
>
> diff --git a/include/linux/suspend.h b/include/linux/suspend.h
> index 8b6ec7e..422e87a 100644
> --- a/include/linux/suspend.h
> +++ b/include/linux/suspend.h
> @@ -384,6 +384,12 @@ extern bool system_entering_hibernation(void);
> extern bool hibernation_available(void);
> asmlinkage int swsusp_save(void);
> extern struct pbe *restore_pblist;
> +extern bool in_resume_hibernate;

in_resume_hibernation? But it is pretty sad if we need another such
state function...
Pavel

> +static inline bool hibernation_in_resume(void)
> +{
> + return in_resume_hibernate;
> +}
> #else /* CONFIG_HIBERNATION */
> static inline void register_nosave_region(unsigned long b, unsigned long e) {}
> static inline void register_nosave_region_late(unsigned long b, unsigned long e) {}
> @@ -395,6 +401,7 @@ static inline void hibernation_set_ops(const struct platform_hibernation_ops *op
> static inline int hibernate(void) { return -ENOSYS; }
> static inline bool system_entering_hibernation(void) { return false; }
> static inline bool hibernation_available(void) { return false; }
> +static inline bool hibernation_in_resume(void) { return false; }
> #endif /* CONFIG_HIBERNATION */
>
> /* Hibernation and suspend events */
> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
> index fca9254..41be909 100644
> --- a/kernel/power/hibernate.c
> +++ b/kernel/power/hibernate.c
> @@ -43,6 +43,7 @@ static char resume_file[256] = CONFIG_PM_STD_PARTITION;
> dev_t swsusp_resume_device;
> sector_t swsusp_resume_block;
> __visible int in_suspend __nosavedata;
> +bool in_resume_hibernate;
>
> enum {
> HIBERNATION_INVALID,
> @@ -433,6 +434,7 @@ static int resume_target_kernel(bool platform_mode)
> if (error)
> goto Cleanup;
>
> + in_resume_hibernate = true;
> error = disable_nonboot_cpus();
> if (error)
> goto Enable_cpus;
> @@ -474,6 +476,7 @@ static int resume_target_kernel(bool platform_mode)
> local_irq_enable();
>
> Enable_cpus:
> + in_resume_hibernate = false;
> enable_nonboot_cpus();
>
> Cleanup:

--
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