From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752576AbdKHUik (ORCPT ); Wed, 8 Nov 2017 15:38:40 -0500 Received: from mail.kernel.org ([198.145.29.99]:38732 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752528AbdKHUif (ORCPT ); Wed, 8 Nov 2017 15:38:35 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 699D2217C0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=helgaas@kernel.org Date: Wed, 8 Nov 2017 14:38:33 -0600 From: Bjorn Helgaas To: "Rafael J. Wysocki" Cc: Linux PM , Bjorn Helgaas , Alan Stern , Greg Kroah-Hartman , LKML , Linux ACPI , Linux PCI , Linux Documentation , Mika Westerberg , Ulf Hansson , Andy Shevchenko , Kevin Hilman Subject: Re: [PATCH v2 2/6] PCI / PM: Support for LEAVE_SUSPENDED driver flag Message-ID: <20171108203833.GA21597@bhelgaas-glaptop.roam.corp.google.com> References: <3806130.B2KCK0tvef@aspire.rjw.lan> <16592954.7Zo1mAdIIH@aspire.rjw.lan> <6330680.LdxjlP4uri@aspire.rjw.lan> <125862518.pYVN4SKj76@aspire.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <125862518.pYVN4SKj76@aspire.rjw.lan> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 08, 2017 at 02:28:18PM +0100, Rafael J. Wysocki wrote: > 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 > --- > 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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html