From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932445Ab3FRNb5 (ORCPT ); Tue, 18 Jun 2013 09:31:57 -0400 Received: from hydra.sisk.pl ([212.160.235.94]:41458 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755725Ab3FRNb4 (ORCPT ); Tue, 18 Jun 2013 09:31:56 -0400 From: "Rafael J. Wysocki" To: ACPI Devel Maling List Cc: LKML , Mika Westerberg Subject: [PATCH] ACPI / LPSS: Power up LPSS devices during enumeration Date: Tue, 18 Jun 2013 15:41:15 +0200 Message-ID: <4947718.ocNqGGkags@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.10.0-rc5+; KDE/4.9.5; x86_64; ; ) MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki Commit 7cd8407 (ACPI / PM: Do not execute _PS0 for devices without _PSC during initialization) introduced a regression on some systems with Intel Low-Power Subsystem (LPSS) where some devices need to be powered up during initialization, but their device objects in the ACPI namespace have _PS0 and _PS3 only (without _PSC or power resources). To work around this problem, make the ACPI LPSS driver power up devices it knows about by using a new helper function acpi_device_fix_up_power() that does all of the necessary sanity checks and calls acpi_dev_pm_explicit_set() to put the device into D0. Reported-and-tested-by: Mika Westerberg Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpi_lpss.c | 21 +++++++++++++++------ drivers/acpi/device_pm.c | 20 ++++++++++++++++++++ include/acpi/acpi_bus.h | 1 + 3 files changed, 36 insertions(+), 6 deletions(-) Index: linux-pm/drivers/acpi/acpi_lpss.c =================================================================== --- linux-pm.orig/drivers/acpi/acpi_lpss.c +++ linux-pm/drivers/acpi/acpi_lpss.c @@ -280,15 +280,24 @@ static int acpi_lpss_create_device(struc if (dev_desc->clk_required) { ret = register_device_clock(adev, pdata); if (ret) { - /* - * Skip the device, but don't terminate the namespace - * scan. - */ - kfree(pdata); - return 0; + /* Skip the device, but continue the namespace scan. */ + ret = 0; + goto err_out; } } + /* + * This works around a known issue in ACPI tables where LPSS devices + * have _PS0 and _PS3 without _PSC (and no power resources), so + * acpi_bus_init_power() will assume that the BIOS has put them into D0. + */ + ret = acpi_device_fix_up_power(adev); + if (ret) { + /* Skip the device, but continue the namespace scan. */ + ret = 0; + goto err_out; + } + adev->driver_data = pdata; ret = acpi_create_platform_device(adev, id); if (ret > 0) Index: linux-pm/drivers/acpi/device_pm.c =================================================================== --- linux-pm.orig/drivers/acpi/device_pm.c +++ linux-pm/drivers/acpi/device_pm.c @@ -288,6 +288,26 @@ int acpi_bus_init_power(struct acpi_devi return 0; } +/** + * acpi_device_fix_up_power - Force device with missing _PSC into D0. + * @device: Device object whose power state is to be fixed up. + * + * Devices without power resources and _PSC, but having _PS0 and _PS3 defined, + * are assumed to be put into D0 by the BIOS. However, in some cases that may + * not be the case and this function should be used then. + */ +int acpi_device_fix_up_power(struct acpi_device *device) +{ + int ret = 0; + + if (!device->power.flags.power_resources + && !device->power.flags.explicit_get + && device->power.state == ACPI_STATE_D0) + ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0); + + return ret; +} + int acpi_bus_update_power(acpi_handle handle, int *state_p) { struct acpi_device *device; Index: linux-pm/include/acpi/acpi_bus.h =================================================================== --- linux-pm.orig/include/acpi/acpi_bus.h +++ linux-pm/include/acpi/acpi_bus.h @@ -372,6 +372,7 @@ const char *acpi_power_state_string(int int acpi_device_get_power(struct acpi_device *device, int *state); int acpi_device_set_power(struct acpi_device *device, int state); int acpi_bus_init_power(struct acpi_device *device); +int acpi_device_fix_up_power(struct acpi_device *device); int acpi_bus_update_power(acpi_handle handle, int *state_p); bool acpi_bus_power_manageable(acpi_handle handle);