Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758793Ab3GaGs3 (ORCPT ); Wed, 31 Jul 2013 02:48:29 -0400 Received: from mga09.intel.com ([134.134.136.24]:3324 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758203Ab3GaGs0 (ORCPT ); Wed, 31 Jul 2013 02:48:26 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.89,785,1367996400"; d="scan'208";a="354712064" Message-ID: <51F8B35A.6000804@intel.com> Date: Wed, 31 Jul 2013 14:48:58 +0800 From: Aaron Lu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: "Rafael J. Wysocki" CC: ACPI Devel Maling List , LKML , Linux PM list , Yinghai Lu , Bjorn Helgaas , Tejun Heo , linux-ide@vger.kernel.org Subject: Re: [PATCH 1/3] ACPI / PM: Only set power states of devices that are power manageable References: <10433383.dueoNg39qi@vostro.rjw.lan> <3386345.rYEkrXssx8@vostro.rjw.lan> <51F6FE34.2020703@intel.com> <1738639.5UcWLydKxR@vostro.rjw.lan> In-Reply-To: <1738639.5UcWLydKxR@vostro.rjw.lan> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3580 Lines: 89 On 07/30/2013 10:04 PM, Rafael J. Wysocki wrote: > On Tuesday, July 30, 2013 07:43:48 AM Aaron Lu wrote: >> On 07/30/2013 06:21 AM, Rafael J. Wysocki wrote: >>> On Monday, July 29, 2013 10:09:53 PM Aaron Lu wrote: >>>> On 07/27/2013 09:10 PM, Rafael J. Wysocki wrote: >>>>> From: Rafael J. Wysocki >>>>> >>>>> 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. >>> >>> So you didn't actually looked at acpi_bus_get_power_flags() that set the >>> power.states[].flags.valid flag, because If you had looked at it, you would >>> have seen that that's not the case. >>> >>> No, we don't set the valid flag for devices that aren't power manageable >>> (i.e. have flags.power_manageable unset), which is the *whole* *point* of >>> this change. >> >> Right, I missed this. Sorry for the noise. >> >>> >>>> 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? >>> >>> No, the original acpi_device_set_power() will return -ENODEV then, but >>> in my opinion returning -EINVAL is more accurate, because "power >>> manageable" means "you can change power state of it". >> >> Shall I prepare a patch to update the errno in acpi_bus_set_power? > > In fact, it doesn't need to check flags.power_manageable after this patch > and the debug message won't be missed I think, so please just remove > the whole if () from there, if that's not a problem. Patch to remove the redundant check, apply on top of this one. From: Aaron Lu Subject: [PATCH 1/3] ACPI / PM: Remove redundant check for power manageable in acpi_bus_set_power Now that we will check if a device is power manageable in acpi_device_set_power, it is no longer necessary to do this check in acpi_bus_set_power, so remove it. Signed-off-by: Aaron Lu --- drivers/acpi/device_pm.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index 63324b8..8270711 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -245,13 +245,6 @@ int acpi_bus_set_power(acpi_handle handle, int state) if (result) return result; - if (!device->flags.power_manageable) { - ACPI_DEBUG_PRINT((ACPI_DB_INFO, - "Device [%s] is not power manageable\n", - dev_name(&device->dev))); - return -ENODEV; - } - return acpi_device_set_power(device, state); } EXPORT_SYMBOL(acpi_bus_set_power); -- 1.8.3.2.10.g43d11f4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/