From mboxrd@z Thu Jan 1 00:00:00 1970 From: Witold Szczeponik Subject: [PATCH] PNPACPI: Enable Power Management Date: Sun, 23 Nov 2008 22:09:03 +0100 Message-ID: <4929C66F.1040206@gmx.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.gmx.net ([213.165.64.20]:53989 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1750870AbYKWVJL (ORCPT ); Sun, 23 Nov 2008 16:09:11 -0500 Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: linux-acpi@vger.kernel.org Cc: linux-kernel@vger.kernel.org Subject: Enable PNPACI Power Management This patch sets 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. The patch is applied against 2.6.27.7 (vanilla). Signed-off-by: Witold Szczeponik Index: linux/drivers/pnp/pnpacpi/core.c =================================================================== --- linux.orig/drivers/pnp/pnpacpi/core.c +++ linux/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