pnpacpi: enable Power Management

PATCH In review [email protected] 1 participant 1 message Dec 1, 2008

Subsystems (2)

ACPI Pnp support

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2008-12-01 22:13 UTC #0 lore raw

PATCH 3/3 pnpacpi: enable Power Management

From: Witold Szczeponik <[email protected]>

Set the power of PnP ACPI devices to D0 when they are activated and to D3 when they are disabled. The latter is in correspondence with the ACPI 3.0 specification, whereas the former is added in order to be able to power up a device after it has been previously disabled (or when booting up a system). (As a consequence, the patch makes the PnP ACPI code more ACPI compliant.)

The patch fixes the problem with some IBM ThinkPads (at least the 600E and the 600X) where the serial ports have a dedicated power source that needs to be brought up before the serial port can be used. Without this patch, the serial port is enabled but has no power.

No regressions were observed on hardware that does not require this patch.

Signed-off-by Witold Szczeponik <[email protected]>

Cc Bjorn Helgaas <[email protected]>

Cc Len Brown <[email protected]>

Cc "Rafael J. Wysocki" <[email protected]>

Signed-off-by Andrew Morton <[email protected]>

---

 drivers/pnp/pnpacpi/core.c |   14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

drivers/pnp/pnpacpi/core.c renamed from drivers/pnp/pnpacpi/core.c~pnpacpi-enable-power-management +10 -4

diff -puN drivers/pnp/pnpacpi/core.c~pnpacpi-enable-power-management drivers/pnp/pnpacpi/core.c
@@ -98,18 +98,24 @@ static int pnpacpi_set_resources(struct 
 	status = acpi_set_current_resources(handle, &buffer);
 	if (ACPI_FAILURE(status))
 		ret = -EINVAL;
+	else if (acpi_bus_power_manageable(handle))
+		ret = acpi_bus_set_power(handle, ACPI_STATE_D0);
 	kfree(buffer.pointer);
 	return ret;
 }
 
 static int pnpacpi_disable_resources(struct pnp_dev *dev)
 {
+	acpi_handle handle = dev->data;
+	int ret = 0;
 	acpi_status status;
 
-	/* acpi_unregister_gsi(pnp_irq(dev, 0)); */
-	status = acpi_evaluate_object((acpi_handle) dev->data,
-				      "_DIS", NULL, NULL);
-	return ACPI_FAILURE(status) ? -ENODEV : 0;
+	if (acpi_bus_power_manageable(handle))
+		ret = acpi_bus_set_power(handle, ACPI_STATE_D3);
+	status = acpi_evaluate_object(handle, "_DIS", NULL, NULL);
+	if (ACPI_FAILURE(status))
+		ret = -ENODEV;
+	return ret;
 }
 
 #ifdef CONFIG_ACPI_SLEEP