Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753823Ab2EDIOj (ORCPT ); Fri, 4 May 2012 04:14:39 -0400 Received: from mga14.intel.com ([143.182.124.37]:42313 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752771Ab2EDIN5 (ORCPT ); Fri, 4 May 2012 04:13:57 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="138801446" From: Huang Ying To: Bjorn Helgaas Cc: ming.m.lin@intel.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, "Rafael J. Wysocki" , Huang Ying , Zheng Yan Subject: [RFC v2 4/5] ACPI, PM, Specify lowest allowed state for device sleep state Date: Fri, 4 May 2012 16:13:40 +0800 Message-Id: <1336119221-21146-5-git-send-email-ying.huang@intel.com> X-Mailer: git-send-email 1.7.10 In-Reply-To: <1336119221-21146-1-git-send-email-ying.huang@intel.com> References: <1336119221-21146-1-git-send-email-ying.huang@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4095 Lines: 116 Lower device sleep state can save more power, but has more exit latency too. Sometimes, to satisfy some power QoS and other requirement, we need to constrain the lowest device sleep state. In this patch, a parameter to specify lowest allowed state for acpi_pm_device_sleep_state is added. So that the caller can enforce the constraint via the parameter. Signed-off-by: Huang Ying --- drivers/acpi/sleep.c | 18 +++++++++++++++--- drivers/pci/pci-acpi.c | 3 ++- drivers/pnp/pnpacpi/core.c | 4 ++-- include/acpi/acpi_bus.h | 6 +++--- 4 files changed, 22 insertions(+), 9 deletions(-) --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -677,6 +677,7 @@ int acpi_suspend(u32 acpi_state) * @dev: device to examine; its driver model wakeup flags control * whether it should be able to wake up the system * @d_min_p: used to store the upper limit of allowed states range + * @d_max_in: specify the lowest allowed states * Return value: preferred power state of the device on success, -ENODEV on * failure (ie. if there's no 'struct acpi_device' for @dev) * @@ -693,7 +694,7 @@ int acpi_suspend(u32 acpi_state) * via @wake. */ -int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p) +int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in) { acpi_handle handle = DEVICE_ACPI_HANDLE(dev); struct acpi_device *adev; @@ -704,11 +705,14 @@ int acpi_pm_device_sleep_state(struct de printk(KERN_DEBUG "ACPI handle has no context!\n"); return -ENODEV; } + d_max_in = clamp_t(int, d_max_in, ACPI_STATE_D0, ACPI_STATE_D3); acpi_method[2] = '0' + acpi_target_sleep_state; /* - * If the sleep state is S0, we will return D3, but if the device has - * _S0W, we will use the value from _S0W + * If the sleep state is S0, the lowest limit from ACPI is D3, + * but if the device has _S0W, we will use the value from _S0W + * as the lowest limit from ACPI. Finally, we will constrain + * the lowest limit with the specified one. */ d_min = ACPI_STATE_D0; d_max = ACPI_STATE_D3; @@ -754,6 +758,14 @@ int acpi_pm_device_sleep_state(struct de if (d_min_p) *d_min_p = d_min; + /* constrain d_max with specified lowest limit (max number) */ + if (d_max > d_max_in) { + d_max = d_max_in; + for (;d_max > d_min; d_max--) { + if (adev->power.states[d_max].flags.valid) + break; + } + } return d_max; } #endif /* CONFIG_PM */ --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -189,7 +189,8 @@ static pci_power_t acpi_pci_choose_state { int acpi_state; - acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL); + acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, + ACPI_STATE_D3); if (acpi_state < 0) return PCI_POWER_ERROR; --- a/drivers/pnp/pnpacpi/core.c +++ b/drivers/pnp/pnpacpi/core.c @@ -170,8 +170,8 @@ static int pnpacpi_suspend(struct pnp_de } if (acpi_bus_power_manageable(handle)) { - int power_state = acpi_pm_device_sleep_state(&dev->dev, NULL); - + int power_state = acpi_pm_device_sleep_state(&dev->dev, NULL, + ACPI_STATE_D3); if (power_state < 0) power_state = (state.event == PM_EVENT_ON) ? ACPI_STATE_D0 : ACPI_STATE_D3; --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -383,13 +383,13 @@ int acpi_enable_wakeup_device_power(stru int acpi_disable_wakeup_device_power(struct acpi_device *dev); #ifdef CONFIG_PM -int acpi_pm_device_sleep_state(struct device *, int *); +int acpi_pm_device_sleep_state(struct device *, int *, int); #else -static inline int acpi_pm_device_sleep_state(struct device *d, int *p) +static inline int acpi_pm_device_sleep_state(struct device *d, int *p, int m) { if (p) *p = ACPI_STATE_D0; - return ACPI_STATE_D3; + return m == ACPI_STATE_D3 ? m : ACPI_STATE_D0; } #endif -- 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/