From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751668AbbAAWQV (ORCPT ); Thu, 1 Jan 2015 17:16:21 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:56221 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751450AbbAAWQT (ORCPT ); Thu, 1 Jan 2015 17:16:19 -0500 From: "Rafael J. Wysocki" To: ACPI Devel Maling List Cc: Linux PM list , Mika Westerberg , Linux Kernel Mailing List Subject: [PATCH] ACPI / PM: Fix PM initialization for devices that are not present Date: Thu, 01 Jan 2015 23:38:28 +0100 Message-ID: <4453924.d7c5RYZUJi@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.16.0-rc5+; KDE/4.11.5; 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 If an ACPI device object whose _STA returns 0 (not present and not functional) has _PR0 or _PS0, its power_manageable flag will be set and acpi_bus_init_power() will return 0 for it. Consequently, if such a device object is passed to the ACPI device PM functions, they will attempt to carry out the requested operation on the device, although they should not do that for devices that are not present. To fix that problem make acpi_bus_init_power() return an error code for devices that are not present which will cause power_manageable to be cleared for them as appropriate in acpi_bus_get_power_flags(). However, the lists of power resources should not be freed for the device in that case, so modify acpi_bus_get_power_flags() to keep those lists even if acpi_bus_init_power() returns an error. Accordingly, when deciding whether or not the lists of power resources need to be freed, acpi_free_power_resources_lists() should check the power.flags.power_resources flag instead of flags.power_manageable, so make that change too. Furthermore, if acpi_bus_attach() sees that flags.initialized is unset for the given device, it should reset the power management settings of the device and re-initialize them from scratch instead of relying on the previous settings (the device may have appeared after being not present previously, for example), so make it use the 'valid' flag of the D0 power state as the initial value of flags.power_manageable for it and call acpi_bus_init_power() to discover its current power state. Signed-off-by: Rafael J. Wysocki --- "Stable" material. --- drivers/acpi/device_pm.c | 2 +- drivers/acpi/scan.c | 13 ++++++++----- 2 files changed, 9 insertions(+), 6 deletions(-) Index: linux-pm/drivers/acpi/device_pm.c =================================================================== --- linux-pm.orig/drivers/acpi/device_pm.c +++ linux-pm/drivers/acpi/device_pm.c @@ -257,7 +257,7 @@ int acpi_bus_init_power(struct acpi_devi device->power.state = ACPI_STATE_UNKNOWN; if (!acpi_device_is_present(device)) - return 0; + return -ENXIO; result = acpi_device_get_power(device, &state); if (result) Index: linux-pm/drivers/acpi/scan.c =================================================================== --- linux-pm.orig/drivers/acpi/scan.c +++ linux-pm/drivers/acpi/scan.c @@ -1001,7 +1001,7 @@ static void acpi_free_power_resources_li if (device->wakeup.flags.valid) acpi_power_resources_list_free(&device->wakeup.resources); - if (!device->flags.power_manageable) + if (!device->power.flags.power_resources) return; for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) { @@ -1744,10 +1744,8 @@ static void acpi_bus_get_power_flags(str device->power.flags.power_resources) device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1; - if (acpi_bus_init_power(device)) { - acpi_free_power_resources_lists(device); + if (acpi_bus_init_power(device)) device->flags.power_manageable = 0; - } } static void acpi_bus_get_flags(struct acpi_device *device) @@ -2371,13 +2369,18 @@ static void acpi_bus_attach(struct acpi_ /* Skip devices that are not present. */ if (!acpi_device_is_present(device)) { device->flags.visited = false; + device->flags.power_manageable = 0; return; } if (device->handler) goto ok; if (!device->flags.initialized) { - acpi_bus_update_power(device, NULL); + device->flags.power_manageable = + device->power.states[ACPI_STATE_D0].flags.valid; + if (acpi_bus_init_power(device)) + device->flags.power_manageable = 0; + device->flags.initialized = true; } device->flags.visited = false;