From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754719Ab3BDUPs (ORCPT ); Mon, 4 Feb 2013 15:15:48 -0500 Received: from hydra.sisk.pl ([212.160.235.94]:39239 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754442Ab3BDUPq (ORCPT ); Mon, 4 Feb 2013 15:15:46 -0500 From: "Rafael J. Wysocki" To: Konstantin Khlebnikov Cc: e1000-devel@lists.sourceforge.net, linux-pci@vger.kernel.org, "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Bjorn Helgaas Subject: Re: [PATCH v2 6/7] PCI/PM: warn about incomplete actions in ->runtime_suspend() callback Date: Mon, 04 Feb 2013 21:22:03 +0100 Message-ID: <2146717.YNnkIQ37Mr@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.8.0-rc6; KDE/4.9.5; x86_64; ; ) In-Reply-To: <20130204115612.5569.49895.stgit@zurg> References: <20130204115246.5569.85829.stgit@zurg> <20130204115612.5569.49895.stgit@zurg> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday, February 04, 2013 03:56:12 PM Konstantin Khlebnikov wrote: > Documentation/power/pci.txt says: > | It is expected that the device driver's pm->runtime_suspend() callback will > | not attempt to prepare the device for signaling wakeup or to put it into a > | low-power state. The driver ought to leave these tasks to the PCI subsystem > | that has all of the information necessary to perform them. > > After commit 42eca2302146fed51335b95128e949ee6f54478f > ("PCI: Don't touch card regs after runtime suspend D3") > | If the driver takes care of state saving, don't touch any registers on it. > pci_pm_runtime_suspend() thinks if state has been saved by ->runtime_suspend() > that means device alredy prepared for wakeup and probably no longer accessible. > > Thus driver must either do all actions or leave all these tasks to PCI subsystem. I don't like this one, because it will generate noise for drivers that legitimately use pci_save_state() in their runtime suspend callbacks and know what they are doing. Thanks, Rafael > Signed-off-by: Konstantin Khlebnikov > Cc: Rafael J. Wysocki > Cc: Bjorn Helgaas > Cc: linux-pci@vger.kernel.org > --- > drivers/pci/pci-driver.c | 15 +++++++++++---- > 1 file changed, 11 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index f9aa311..2b0ff9a 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -1009,12 +1009,19 @@ static int pci_pm_runtime_suspend(struct device *dev) > return 0; > } > > - if (!pci_dev->state_saved) { > - pci_save_state(pci_dev); > - pci_finish_runtime_suspend(pci_dev); > + if (pci_dev->state_saved) { > + WARN_ONCE(pci_dev->current_state == prev, > + "PCI PM: Power state of device not changed by %pF\n", > + pm->runtime_suspend); > + WARN_ONCE(pci_dev_run_wake(pci_dev) && > + !pci_dev->wakeup_prepared, > + "PCI PM: Waking of device not configured by %pF\n", > + pm->runtime_suspend); > + return 0; > } > > - return 0; > + pci_save_state(pci_dev); > + return pci_finish_runtime_suspend(pci_dev); > } > > static int pci_pm_runtime_resume(struct device *dev) > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.