Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751784AbdF2Wob (ORCPT ); Thu, 29 Jun 2017 18:44:31 -0400 Received: from cloudserver094114.home.net.pl ([79.96.170.134]:42325 "EHLO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751532AbdF2Wo3 (ORCPT ); Thu, 29 Jun 2017 18:44:29 -0400 From: "Rafael J. Wysocki" To: linux-pci@vger.kernel.org, Bjorn Helgaas , Mika Westerberg Cc: Alan Stern , Kai-Heng Feng , Bjorn Helgaas , gregkh@linuxfoundation.org, USB list , LKML , "Rafael J. Wysocki" , linux-pm@vger.kernel.org Subject: Re: [PATCH v2] PCI / PM: Avoid using device_may_wakeup() for runtime PM Date: Fri, 30 Jun 2017 00:37 +0200 Message-ID: <2254362.EY9ByagAJb@aspire.rjw.lan> User-Agent: KMail/4.14.10 (Linux/4.12.0-rc1+; KDE/4.14.9; x86_64; ; ) In-Reply-To: <2677722.OnHOCzR3UZ@aspire.rjw.lan> References: <2883450.A8OIi7Gmb8@aspire.rjw.lan> <2677722.OnHOCzR3UZ@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 Content-Length: 4725 Lines: 125 On Friday, June 23, 2017 02:58:11 PM Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > pci_target_state() calls device_may_wakeup() which checks whether > or not the device may wake up the system from sleep states, but > pci_target_state() is used for runtime PM too. > > Since runtime PM is expected to always enable remote wakeup if > possible, modify pci_target_state() to take additional argument > indicating whether or not it should look for a state from which > the device can signal wakeup and pass either the return value > of device_can_wakeup(), or "false" (if the device itself is not > wakeup-capable) to it from the code related to runtime PM. > > While at it, fix the comment in pci_dev_run_wake() which is not > about sleep states. > > Signed-off-by: Rafael J. Wysocki > --- > > -> v2: > > Passing "true" as the second argument to pci_target_state() for runtime PM > might trigger suboptimal state choices to be made, so pass the return value > of device_can_wakeup() to it instead and pass "false" to it in pci_dev_run_wake(), > because that assumes device_can_wakeup() to return "false" already. This was sent a week ago without any response so far. Any concerns? > --- > drivers/pci/pci.c | 22 +++++++++++++--------- > 1 file changed, 13 insertions(+), 9 deletions(-) > > Index: linux-pm/drivers/pci/pci.c > =================================================================== > --- linux-pm.orig/drivers/pci/pci.c > +++ linux-pm/drivers/pci/pci.c > @@ -1982,12 +1982,13 @@ EXPORT_SYMBOL(pci_wake_from_d3); > /** > * pci_target_state - find an appropriate low power state for a given PCI dev > * @dev: PCI device > + * @wakeup: Whether or not wakeup functionality will be enabled for the device. > * > * Use underlying platform code to find a supported low power state for @dev. > * If the platform can't manage @dev, return the deepest state from which it > * can generate wake events, based on any available PME info. > */ > -static pci_power_t pci_target_state(struct pci_dev *dev) > +static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup) > { > pci_power_t target_state = PCI_D3hot; > > @@ -2024,7 +2025,7 @@ static pci_power_t pci_target_state(stru > if (dev->current_state == PCI_D3cold) > target_state = PCI_D3cold; > > - if (device_may_wakeup(&dev->dev)) { > + if (wakeup) { > /* > * Find the deepest state from which the device can generate > * wake-up events, make it the target state and enable device > @@ -2050,13 +2051,14 @@ static pci_power_t pci_target_state(stru > */ > int pci_prepare_to_sleep(struct pci_dev *dev) > { > - pci_power_t target_state = pci_target_state(dev); > + bool wakeup = device_may_wakeup(&dev->dev); > + pci_power_t target_state = pci_target_state(dev, wakeup); > int error; > > if (target_state == PCI_POWER_ERROR) > return -EIO; > > - pci_enable_wake(dev, target_state, device_may_wakeup(&dev->dev)); > + pci_enable_wake(dev, target_state, wakeup); > > error = pci_set_power_state(dev, target_state); > > @@ -2089,9 +2091,10 @@ EXPORT_SYMBOL(pci_back_from_sleep); > */ > int pci_finish_runtime_suspend(struct pci_dev *dev) > { > - pci_power_t target_state = pci_target_state(dev); > + pci_power_t target_state; > int error; > > + target_state = pci_target_state(dev, device_can_wakeup(&dev->dev)); > if (target_state == PCI_POWER_ERROR) > return -EIO; > > @@ -2127,8 +2130,8 @@ bool pci_dev_run_wake(struct pci_dev *de > if (!dev->pme_support) > return false; > > - /* PME-capable in principle, but not from the intended sleep state */ > - if (!pci_pme_capable(dev, pci_target_state(dev))) > + /* PME-capable in principle, but not from the target power state */ > + if (!pci_pme_capable(dev, pci_target_state(dev, false))) > return false; > > while (bus->parent) { > @@ -2163,9 +2166,10 @@ EXPORT_SYMBOL_GPL(pci_dev_run_wake); > bool pci_dev_keep_suspended(struct pci_dev *pci_dev) > { > struct device *dev = &pci_dev->dev; > + bool wakeup = device_may_wakeup(dev); > > if (!pm_runtime_suspended(dev) > - || pci_target_state(pci_dev) != pci_dev->current_state > + || pci_target_state(pci_dev, wakeup) != pci_dev->current_state > || platform_pci_need_resume(pci_dev) > || (pci_dev->dev_flags & PCI_DEV_FLAGS_NEEDS_RESUME)) > return false; > @@ -2183,7 +2187,7 @@ bool pci_dev_keep_suspended(struct pci_d > spin_lock_irq(&dev->power.lock); > > if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold && > - !device_may_wakeup(dev)) > + !wakeup) > __pci_pme_active(pci_dev, false); > > spin_unlock_irq(&dev->power.lock); >