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authorKalesh Singh <kaleshsingh@google.com>2022-06-30 19:12:29 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-07-01 10:39:20 +0200
commit261e224d6a5c43e2bb8a07b7662f9b4ec425cfec (patch)
tree396865844df8f25f504e2fe66b52bbce4610d832 /kernel/power
parent80fc671bcc0173836e9032b0c698ea74c13b9d7c (diff)
downloadlinux-261e224d6a5c43e2bb8a07b7662f9b4ec425cfec.tar.gz
pm/sleep: Add PM_USERSPACE_AUTOSLEEP Kconfig
Systems that initiate frequent suspend/resume from userspace
can make the kernel aware by enabling PM_USERSPACE_AUTOSLEEP
config.

This allows for certain sleep-sensitive code (wireguard/rng) to
decide on what preparatory work should be performed (or not) in
their pm_notification callbacks.

This patch was prompted by the discussion at [1] which attempts
to remove CONFIG_ANDROID that currently guards these code paths.

[1] https://lore.kernel.org/r/20220629150102.1582425-1-hch@lst.de/

Suggested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Link: https://lore.kernel.org/r/20220630191230.235306-1-kaleshsingh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/Kconfig20
1 files changed, 20 insertions, 0 deletions
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index a12779650f15..60a1d3051cc7 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -143,6 +143,26 @@ config PM_AUTOSLEEP
 	Allow the kernel to trigger a system transition into a global sleep
 	state automatically whenever there are no active wakeup sources.
 
+config PM_USERSPACE_AUTOSLEEP
+	bool "Userspace opportunistic sleep"
+	depends on PM_SLEEP
+	help
+	Notify kernel of aggressive userspace autosleep power management policy.
+
+	This option changes the behavior of various sleep-sensitive code to deal
+	with frequent userspace-initiated transitions into a global sleep state.
+
+	Saying Y here, disables code paths that most users really should keep
+	enabled. In particular, only enable this if it is very common to be
+	asleep/awake for very short periods of time (<= 2 seconds).
+
+	Only platforms, such as Android, that implement opportunistic sleep from
+	a userspace power manager service should enable this option; and not
+	other machines. Therefore, you should say N here, unless you are
+	extremely certain that this is what you want. The option otherwise has
+	bad, undesirable effects, and should not be enabled just for fun.
+
+
 config PM_WAKELOCKS
 	bool "User space wakeup sources interface"
 	depends on PM_SLEEP