On Fri, Oct 16, 2020 at 5:51 AM Joseph Jang <josephj...@google.com> wrote:
>
> From: josephjang <josephj...@google.com>
>
> Add suspend timeout handler to prevent device stuck during suspend/
> resume process. Suspend timeout handler will dump disk sleep task
> at first round timeout and trigger kernel panic at second round timeout.
> The default timer for each round is 30 seconds.
>
> Note: Can use following command to simulate suspend hang for testing.
> adb shell echo 1 > /sys/power/pm_hang
> adb shell echo mem > /sys/power/state
> Signed-off-by: josephjang <josephj...@google.com>
> ---
> include/linux/console.h | 1 +
> kernel/power/Kconfig | 9 +++
> kernel/power/main.c | 66 ++++++++++++++++
> kernel/power/suspend.c | 162 ++++++++++++++++++++++++++++++++++++++++
> kernel/printk/printk.c | 5 ++
> 5 files changed, 243 insertions(+)
>
> diff --git a/include/linux/console.h b/include/linux/console.h
> index 0670d3491e0e..ac468c602c0b 100644
> --- a/include/linux/console.h
> +++ b/include/linux/console.h
> @@ -192,6 +192,7 @@ static inline void console_sysfs_notify(void)
> { }
> #endif
> extern bool console_suspend_enabled;
> +extern int is_console_suspended(void);
>
> /* Suspend and resume console messages over PM events */
> extern void suspend_console(void);
> diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
> index a7320f07689d..52b7a181b6d8 100644
> --- a/kernel/power/Kconfig
> +++ b/kernel/power/Kconfig
> @@ -207,6 +207,15 @@ config PM_SLEEP_DEBUG
> def_bool y
> depends on PM_DEBUG && PM_SLEEP
>
> +config PM_SLEEP_MONITOR
> + bool "Linux kernel suspend/resume process monitor"
> + depends on PM_SLEEP
> + help
> + This option will enable suspend/resume monitor to prevent device
> + stuck during suspend/resume process. Suspend timeout handler will
> + dump disk sleep task at first round timeout and trigger kernel panic
> + at second round timeout. The default timer for each round is 30
> seconds.
> +
The facility associated with the Kconfig entry right below is supposed
to do exactly the same thing.
What's the reason to add another one? What is missing?
> config DPM_WATCHDOG
> bool "Device suspend/resume watchdog"
> depends on PM_DEBUG && PSTORE && EXPERT
