From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1947375AbdKROqN (ORCPT ); Sat, 18 Nov 2017 09:46:13 -0500 Received: from cloudserver094114.home.net.pl ([79.96.170.134]:47253 "EHLO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966411AbdKROp0 (ORCPT ); Sat, 18 Nov 2017 09:45:26 -0500 From: "Rafael J. Wysocki" To: Linux PM Cc: Bjorn Helgaas , Alan Stern , Greg Kroah-Hartman , LKML , Linux ACPI , Linux PCI , Linux Documentation , Mika Westerberg , Ulf Hansson , Andy Shevchenko , Kevin Hilman Subject: [PATCH v4 2/6] PCI / PM: Support for LEAVE_SUSPENDED driver flag Date: Sat, 18 Nov 2017 15:33:52 +0100 Message-ID: <3189584.p93WhT6c0L@aspire.rjw.lan> In-Reply-To: <1917233.X2U0QN21my@aspire.rjw.lan> References: <3806130.B2KCK0tvef@aspire.rjw.lan> <4184911.zoJM7jZeH4@aspire.rjw.lan> <1917233.X2U0QN21my@aspire.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki Add support for DPM_FLAG_LEAVE_SUSPENDED to the PCI bus type by making it (a) set the power.may_skip_resume status bit for devices that, from its perspective, may be left in suspend after system wakeup from sleep and (b) return early from pci_pm_resume_noirq() for devices whose remaining resume callbacks during the transition under way are going to be skipped by the PM core. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Acked-by: Bjorn Helgaas --- v3 -> v4: No changes. v2 -> v3: Add the Acked-by from Bjorn, no changes in the patch. --- Documentation/power/pci.txt | 11 +++++++++++ drivers/pci/pci-driver.c | 19 +++++++++++++++++-- 2 files changed, 28 insertions(+), 2 deletions(-) Index: linux-pm/drivers/pci/pci-driver.c =================================================================== --- linux-pm.orig/drivers/pci/pci-driver.c +++ linux-pm/drivers/pci/pci-driver.c @@ -699,7 +699,7 @@ static void pci_pm_complete(struct devic pm_generic_complete(dev); /* Resume device if platform firmware has put it in reset-power-on */ - if (dev->power.direct_complete && pm_resume_via_firmware()) { + if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) { pci_power_t pre_sleep_state = pci_dev->current_state; pci_update_current_state(pci_dev, pci_dev->current_state); @@ -783,8 +783,10 @@ static int pci_pm_suspend_noirq(struct d struct pci_dev *pci_dev = to_pci_dev(dev); const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; - if (dev_pm_smart_suspend_and_suspended(dev)) + if (dev_pm_smart_suspend_and_suspended(dev)) { + dev->power.may_skip_resume = true; return 0; + } if (pci_has_legacy_pm_support(pci_dev)) return pci_legacy_suspend_late(dev, PMSG_SUSPEND); @@ -838,6 +840,16 @@ static int pci_pm_suspend_noirq(struct d Fixup: pci_fixup_device(pci_fixup_suspend_late, pci_dev); + /* + * If the target system sleep state is suspend-to-idle, it is sufficient + * to check whether or not the device's wakeup settings are good for + * runtime PM. Otherwise, the pm_resume_via_firmware() check will cause + * pci_pm_complete() to take care of fixing up the device's state + * anyway, if need be. + */ + dev->power.may_skip_resume = device_may_wakeup(dev) || + !device_can_wakeup(dev); + return 0; } @@ -847,6 +859,9 @@ static int pci_pm_resume_noirq(struct de struct device_driver *drv = dev->driver; int error = 0; + if (dev_pm_may_skip_resume(dev)) + return 0; + /* * Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend * during system suspend, so update their runtime PM status to "active" Index: linux-pm/Documentation/power/pci.txt =================================================================== --- linux-pm.orig/Documentation/power/pci.txt +++ linux-pm/Documentation/power/pci.txt @@ -994,6 +994,17 @@ into D0 going forward), but if it is in the function will set the power.direct_complete flag for it (to make the PM core skip the subsequent "thaw" callbacks for it) and return. +Setting the DPM_FLAG_LEAVE_SUSPENDED flag means that the driver prefers the +device to be left in suspend after system-wide transitions to the working state. +This flag is checked by the PM core, but the PCI bus type informs the PM core +which devices may be left in suspend from its perspective (that happens during +the "noirq" phase of system-wide suspend and analogous transitions) and next it +uses the dev_pm_may_skip_resume() helper to decide whether or not to return from +pci_pm_resume_noirq() early, as the PM core will skip the remaining resume +callbacks for the device during the transition under way and will set its +runtime PM status to "suspended" if dev_pm_may_skip_resume() returns "true" for +it. + 3.2. Device Runtime Power Management ------------------------------------ In addition to providing device power management callbacks PCI device drivers