diff mbox series

[4/4] ACPI: battery: Wake system on AC plug or unplug in over s2idle

Message ID 20250208162210.3929473-5-superm1@kernel.org
State New
Headers show
Series Improvements to ACPI battery handling over s2idle | expand

Commit Message

Mario Limonciello Feb. 8, 2025, 4:22 p.m. UTC
From: Mario Limonciello <mario.limonciello@amd.com>

On Windows the OS will wake up when plugged or unplugged from AC adapter.
Depending upon whether the system was plugged in or unplugged will
determine whether the "display turns on".  If there is no user activity
for some time then it goes back to sleep.

In Linux plugging or unplugging an adapter will wake the SoC from HW
sleep but then the Linux kernel puts it right back into HW sleep
immediately unless there is another interrupt active (such as a PME or
GPIO).

To get closer to the Windows behavior, record the state of the battery
when going into suspend and compare it when updating battery status
during the s2idle loop. If it's changed, wake the system.

This can be restored to previous behavior by disabling the ACPI battery
device `power/wakeup` sysfs file.

Link: https://learn.microsoft.com/en-us/windows-hardware/design/device-experiences/modern-standby-wake-sources#environmental-context-changes-1
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/acpi/battery.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Mario Limonciello Feb. 9, 2025, 1:14 p.m. UTC | #1
On 2/8/25 11:59, Rafael J. Wysocki wrote:
> On Sat, Feb 8, 2025 at 5:22 PM Mario Limonciello <superm1@kernel.org> wrote:
>>
>> From: Mario Limonciello <mario.limonciello@amd.com>
>>
>> On Windows the OS will wake up when plugged or unplugged from AC adapter.
>> Depending upon whether the system was plugged in or unplugged will
>> determine whether the "display turns on".  If there is no user activity
>> for some time then it goes back to sleep.
>>
>> In Linux plugging or unplugging an adapter will wake the SoC from HW
>> sleep but then the Linux kernel puts it right back into HW sleep
>> immediately unless there is another interrupt active (such as a PME or
>> GPIO).
>>
>> To get closer to the Windows behavior, record the state of the battery
>> when going into suspend and compare it when updating battery status
>> during the s2idle loop. If it's changed, wake the system.
>>
>> This can be restored to previous behavior by disabling the ACPI battery
>> device `power/wakeup` sysfs file.
> 
> Why is this desirable?
> 
> What if the AC is connected to a suspended laptop when the lid is
> still closed?  Is it really a good idea to resume it then?

Yes; that's the exact situation I wanted this to work.  I have a dock 
connected to some monitors, power supply, keyboard, and mouse.  I want 
the machine to wake up when it's connected to the dock but still closed.

That's how Windows works at least.

> 
> Frankly, I'd prefer the existing behavior to be still the default.

Since this is hooking into the existing wakeups that can happen for 
battery I guess that there isn't a good way to configure one but not the 
other.

Would it be better to do something similar in the ACPI power supply device?

> 
>> Link: https://learn.microsoft.com/en-us/windows-hardware/design/device-experiences/modern-standby-wake-sources#environmental-context-changes-1
>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>> ---
>>   drivers/acpi/battery.c | 8 ++++++++
>>   1 file changed, 8 insertions(+)
>>
>> diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
>> index 72c8a509695e6..91f79927cc720 100644
>> --- a/drivers/acpi/battery.c
>> +++ b/drivers/acpi/battery.c
>> @@ -125,6 +125,7 @@ struct acpi_battery {
>>          int state;
>>          int power_unit;
>>          int capacity_suspend;
>> +       int suspend_state;
>>          unsigned long flags;
>>   };
>>
>> @@ -1012,6 +1013,12 @@ static inline bool acpi_battery_should_wake(struct acpi_battery *battery)
>>                  return true;
>>          }
>>
>> +       if (battery->state != battery->suspend_state) {
>> +               pm_pr_dbg("Waking due to battery state changed from 0x%x to 0x%x",
>> +                         battery->suspend_state, battery->state);
>> +               return true;
>> +       }
>> +
>>          return false;
>>   }
>>
>> @@ -1313,6 +1320,7 @@ static int acpi_battery_suspend(struct device *dev)
>>                  return -EINVAL;
>>
>>          battery->capacity_suspend = battery->capacity_now;
>> +       battery->suspend_state = battery->state;
>>
>>          return 0;
>>   }
>> --
>> 2.43.0
>>
>>
diff mbox series

Patch

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 72c8a509695e6..91f79927cc720 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -125,6 +125,7 @@  struct acpi_battery {
 	int state;
 	int power_unit;
 	int capacity_suspend;
+	int suspend_state;
 	unsigned long flags;
 };
 
@@ -1012,6 +1013,12 @@  static inline bool acpi_battery_should_wake(struct acpi_battery *battery)
 		return true;
 	}
 
+	if (battery->state != battery->suspend_state) {
+		pm_pr_dbg("Waking due to battery state changed from 0x%x to 0x%x",
+			  battery->suspend_state, battery->state);
+		return true;
+	}
+
 	return false;
 }
 
@@ -1313,6 +1320,7 @@  static int acpi_battery_suspend(struct device *dev)
 		return -EINVAL;
 
 	battery->capacity_suspend = battery->capacity_now;
+	battery->suspend_state = battery->state;
 
 	return 0;
 }