From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f173.google.com ([209.85.217.173]:63942 "EHLO mail-lb0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751631Ab3AaHFZ (ORCPT ); Thu, 31 Jan 2013 02:05:25 -0500 Message-ID: <510A17AF.6030906@openvz.org> Date: Thu, 31 Jan 2013 11:05:19 +0400 From: Konstantin Khlebnikov MIME-Version: 1.0 To: "Rafael J. Wysocki" CC: Bjorn Helgaas , linux-kernel@vger.kernel.org, e1000-devel@lists.sourceforge.net, linux-pci@vger.kernel.org, Bruce Allan , Jeff Kirsher , "Rafael J. Wysocki" Subject: Re: [PATCH 1/5] e1000e: fix resuming from runtime-suspend References: <20130118113019.6698.25941.stgit@zurg> <12263202.uQHxo0zU24@vostro.rjw.lan> <51076CEE.8050706@openvz.org> <1546399.qHCL89Xptv@vostro.rjw.lan> In-Reply-To: <1546399.qHCL89Xptv@vostro.rjw.lan> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-pci-owner@vger.kernel.org List-ID: Rafael J. Wysocki wrote: > On Tuesday, January 29, 2013 10:32:14 AM Konstantin Khlebnikov wrote: >> Rafael J. Wysocki wrote: >>> On Monday, January 28, 2013 04:05:33 PM Bjorn Helgaas wrote: >>>> [+cc Rafael, author of patch you cited] >>>> >>>> On Fri, Jan 18, 2013 at 4:42 AM, Konstantin Khlebnikov >>>> wrote: >>>>> Bug was introduced in commit 23606cf5d1192c2b17912cb2ef6e62f9b11de133 >>>>> ("e1000e / PCI / PM: Add basic runtime PM support (rev. 4)") in v2.6.35 >>>>> >>>>> Signed-off-by: Konstantin Khlebnikov >>>>> Cc: e1000-devel@lists.sourceforge.net >>>>> Cc: Jeff Kirsher >>>>> Cc: Bruce Allan >>>>> --- >>>>> drivers/net/ethernet/intel/e1000e/netdev.c | 13 ++++++++----- >>>>> 1 file changed, 8 insertions(+), 5 deletions(-) >>>>> >>>>> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c >>>>> index fbf75fd..2853c11 100644 >>>>> --- a/drivers/net/ethernet/intel/e1000e/netdev.c >>>>> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c >>>>> @@ -5691,14 +5691,17 @@ static int e1000_runtime_suspend(struct device *dev) >>>>> struct pci_dev *pdev = to_pci_dev(dev); >>>>> struct net_device *netdev = pci_get_drvdata(pdev); >>>>> struct e1000_adapter *adapter = netdev_priv(netdev); >>>>> + int retval; >>>>> + bool wake; >>>>> >>>>> - if (e1000e_pm_ready(adapter)) { >>>>> - bool wake; >>>>> + if (!e1000e_pm_ready(adapter)) >>>>> + return 0; >>>>> >>>>> - __e1000_shutdown(pdev,&wake, true); >>>>> - } >>>>> + retval = __e1000_shutdown(pdev,&wake, true); >>>>> + if (!retval) >>>>> + e1000_power_off(pdev, true, wake); >>>>> >>>>> - return 0; >>>>> + return retval; >>>>> } >>>>> >>>>> static int e1000_idle(struct device *dev) >>>>> >>> >>> I'd like the changelog to say what the bug is and how it is being fixed in >>> general terms. >> >> Ok, my bad. >> >> Problem: ethernet device does not work (no carrier signal). >> Right after boot it goes to runtime-suspend and never wake up. >> >> Original code (before your commit) calls pci_prepare_to_sleep() and it >> calls pci_enable_wake() and switches device to one of D3 state. > > The original code in what function? Oh, I screwed up again. That commit adds support of runtime-pm, so there is no original code. But runtime-pm in 'igb' works in this way: igb_runtime_suspend() -> pci_prepare_to_sleep() -> pci_enable_wake() > >> It seems redundant, because pci_pm_runtime_suspend() do the same thing >> after calling ->runtime_suspend callback. Or rather it did it before commit >> 42eca2302146fed51335b95128e949ee6f54478f ("PCI: Don't touch card regs after >> runtime suspend D3") and third patch aimed fix this damage. >> >> More over seems like calling pci_enable_wake() from e1000e isn't enough for my case, >> because my enthernet cannot wakeup from runtime-suspend without third patch. > > Which third patch? third patch in this patchset: "[PATCH 3/5] PCI: revert preparing for wakeup in runtime-suspend finalization" > >> Seems like it's because pci_enable_wake() and pci_finish_runtime_suspend() >> calls different pratform-pm callbacks -- platform_pci_run_wake() / >> platform_pci_sleep_wake(). > > That's correct, for historical reasons. We'll need to merge these things, but > for now the are separate (because of the way ACPI handles system suspend and > runtime PM). Ok, I have not read yet all code and documentation. But it seems runtime-pm engine needs some sort of runtime debug-mode which would warn about strange or ineffective actions in drivers, probably just script for parsing kernel-log and tracking states for all devices and buses. > > Thanks, > Rafael > >