The ACPI subsystem is responsible for managing the power and wake
sources for an ACPI device. By explicitly calling
device_set_wakeup_capable, we are circumvent the ACPI subsystem and
setting wake capabilities on the device when it doesn't support it.
Take the following example:
* We have an ACPI HID device that has `_PR0` and `_PR3`. It doesn't have
`_PRW` so that means the device can't wake the system.
* The IRQ line is active level low for this device and is pulled up by the
power resource defined in `_PR0`/`_PR3`.
Since the i2c-hid driver has set the device as wake capable, the wake
pin gets enabled on suspend. As part of suspend, ACPI will power down
the device since it's not a wake source. When the device is powered
down, the IRQ line will drop, and it will trigger a wake event.
See the following debug log:
[ 42.335804] PM: Suspending system (s2idle)
[ 42.340186] amd_gpio AMD0030:00: RX: Setting wake for pin 89 to enable
[ 42.467736] power-0416 __acpi_power_off : Power resource [PR00] turned off
[ 42.467739] device_pm-0280 device_set_power : Device [H05D] transitioned to D3cold
[ 42.475210] PM: pm_system_irq_wakeup: 11 triggered pinctrl_amd
[ 42.535293] PM: Wakeup unrelated to ACPI SCI
[ 42.535294] PM: resume from suspend-to-idle
Signed-off-by: Raul E Rangel <rrangel@xxxxxxxxxxxx>
---
drivers/hid/i2c-hid/i2c-hid-acpi.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi.c b/drivers/hid/i2c-hid/i2c-hid-acpi.c
index a6f0257a26de..fc311a19a19d 100644
--- a/drivers/hid/i2c-hid/i2c-hid-acpi.c
+++ b/drivers/hid/i2c-hid/i2c-hid-acpi.c
@@ -105,11 +105,6 @@ static int i2c_hid_acpi_probe(struct i2c_client *client)
acpi_device_fix_up_power(adev);
- if (acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) {
- device_set_wakeup_capable(dev, true);
- device_set_wakeup_enable(dev, false);
- }
-
return i2c_hid_core_probe(client, &ihid_acpi->ops,
hid_descriptor_address);
}
--
2.34.1.307.g9b7440fafd-goog
