[PATCH v2 1/2] PM: enable support for imminent power loss
From: <hidden>
Date: 2021-07-26 13:23:28
Also in:
linux-nvme, lkml
Subsystem:
hibernation (aka software suspend, aka swsusp), suspend to ram, the rest · Maintainers:
"Rafael J. Wysocki", Linus Torvalds
From: Shivamurthy Shastri <redacted> If the shutdown is pwerformed when the platform is running on the limited backup power supply, some of the devices might not have enough power to perform a clean shutdown. It is necessary to inform the driver about the limited backup power supply, to allow the driver to decide to perform the minimal required operation for a fast and clean shutdown. Signed-off-by: Keith Busch <kbush@kernel.org> Signed-off-by: Shivamurthy Shastri <redacted> --- include/linux/suspend.h | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-)
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 8af13ba60c7e..1898792c10d3 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h@@ -210,9 +210,10 @@ extern int suspend_valid_only_mem(suspend_state_t state); extern unsigned int pm_suspend_global_flags; -#define PM_SUSPEND_FLAG_FW_SUSPEND BIT(0) -#define PM_SUSPEND_FLAG_FW_RESUME BIT(1) -#define PM_SUSPEND_FLAG_NO_PLATFORM BIT(2) +#define PM_SUSPEND_FLAG_FW_SUSPEND BIT(0) +#define PM_SUSPEND_FLAG_FW_RESUME BIT(1) +#define PM_SUSPEND_FLAG_NO_PLATFORM BIT(2) +#define PM_SUSPEND_FLAG_POWER_LOSS_IMMINENT BIT(3) static inline void pm_suspend_clear_flags(void) {
@@ -234,6 +235,11 @@ static inline void pm_set_suspend_no_platform(void) pm_suspend_global_flags |= PM_SUSPEND_FLAG_NO_PLATFORM; } +static inline void pm_set_power_loss_imminent(void) +{ + pm_suspend_global_flags |= PM_SUSPEND_FLAG_POWER_LOSS_IMMINENT; +} + /** * pm_suspend_via_firmware - Check if platform firmware will suspend the system. *
@@ -291,6 +297,22 @@ static inline bool pm_suspend_no_platform(void) return !!(pm_suspend_global_flags & PM_SUSPEND_FLAG_NO_PLATFORM); } +/** + * pm_power_loss_imminent - Check if platform is running on limited backup power + * source + * + * To be called during system-wide power management transitions to sleep states. + * + * Return 'true' if power loss may be imminent due to platform running on + * limited backup supply. If set during a shutdown, drivers should use any + * available shortcuts to prepare their device for abrupt power loss. + */ +static inline bool pm_power_loss_imminent(void) +{ + return !!(pm_suspend_global_flags & + PM_SUSPEND_FLAG_POWER_LOSS_IMMINENT); +} + /* Suspend-to-idle state machnine. */ enum s2idle_states { S2IDLE_STATE_NONE, /* Not suspended/suspending. */
--
2.25.1