Re: [PATCH 1/3] ACPI / PM: Only set power states of devices that are power manageable
From: Aaron Lu <hidden>
Date: 2013-07-29 14:09:31
Also in:
linux-acpi, linux-pm, lkml
On 07/27/2013 09:10 PM, Rafael J. Wysocki wrote:
From: Rafael J. Wysocki <redacted> Make acpi_device_set_power() check if the given device is power manageable before checking if the given power state is valid for that device. Otherwise it will print that "Device does not support" that power state into the kernel log, which may not make sense for some power states (D0 and D3cold are supported by all devices by definition).
It will not print "Device does not support" that power state if that power state is D0 or D3cold since we have unconditionally set those two power state's valid flag. OTOH, what value should we return for a device node that is not power manageable in acpi_device_set_power when the target state is D0 or D3 cold? The old behavior is to return 0, meanning success without taking any actual action. In acpi_bus_set_power, if the device is not power manageable, we will return -ENODEV; in acpi_dev_pm_full/low_power, we will return 0 as in the original acpi_device_set_power. So return -EINVAL here is correct? -Aaron
quoted hunk ↗ jump to hunk
Tested-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Rafael J. Wysocki <redacted> --- drivers/acpi/device_pm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) Index: linux-pm/drivers/acpi/device_pm.c ===================================================================--- linux-pm.orig/drivers/acpi/device_pm.c +++ linux-pm/drivers/acpi/device_pm.c@@ -159,7 +159,8 @@ int acpi_device_set_power(struct acpi_de int result = 0; bool cut_power = false; - if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD)) + if (!device || !device->flags.power_manageable + || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD)) return -EINVAL; /* Make sure this is a valid target state */