Re: [Updated patch] Re: [PATCH] igb: fix kexec with igb
From: Rafael J. Wysocki
Date: Sun Mar 29 2009 - 07:19:34 EST
On Sunday 29 March 2009, Jeff Kirsher wrote:
> On Sat, Mar 28, 2009 at 2:27 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> > On Tuesday 24 March 2009, Yinghai Lu wrote:
> >> Rafael J. Wysocki wrote:
> >> > On Thursday 12 March 2009, Yinghai Lu wrote:
> >> >> Rafael J. Wysocki wrote:
> >> >>> On Sunday 08 March 2009, Rafael J. Wysocki wrote:
> >> >>>> On Sunday 08 March 2009, Yinghai Lu wrote:
> >> >>>>> Rafael J. Wysocki wrote:
> >> >>>>>> On Saturday 07 March 2009, Yinghai Lu wrote:
> >> >>>>>>> On Fri, Mar 6, 2009 at 11:18 PM, Jesse Brandeburg
> >> >>>>>>> <jesse.brandeburg@xxxxxxxxx> wrote:
> >> >>>>>>>> On Fri, Mar 6, 2009 at 8:33 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> >> >>>>>>>>> Impact: could probe igb
> >> >>>>>>>>>
> >> >>>>>>>>> Found one system with 82575EB, in the kernel that is kexeced, probe igb
> >> >>>>>>>>> failed with -2.
> >> >>>>>>>>>
> >> >>>>>>>>> it looks like the same behavior happened on forcedeth.
> >> >>>>>>>>>
> >> >>>>>>>>> try to check system_state to make sure if put it on D3
> >> >>>>>>>>>
> >> >>>>>>>>> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> >> >>>>>>>>>
> >> >>>>>>>>> ---
> >> >>>>>>>>> drivers/net/igb/igb_main.c | 19 ++++++++++++++-----
> >> >>>>>>>>> 1 file changed, 14 insertions(+), 5 deletions(-)
> >> >>>>>>>> I see the point of the patch, but I know for a fact that ixgbe when
> >> >>>>>>>> enabled for MSI-X also doesn't work with kexec.
> >> >>>>>>>>
> >> >>>>>>>> so my questions are:
> >> >>>>>>>> are you going to change every driver?
> >> >>>>>>> i tend to only change driver that i have related HW.
> >> >>>>>>>
> >> >>>>>>>> why can't this be fixed in core kernel code instead?
> >> >>>>>>> will check it.
> >> >>>>>>>
> >> >>>>>>>> Shouldn't pci_enable_device take it out of D3?
> >> >>>>>>>> Or maybe it should be taken out of D3 immediately if someone tries to
> >> >>>>>>>> ioremap any of the BARx registers?
> >> >>>>>>> looks like second kernel can not detect the state any more.
> >> >>>>>> In fact pci_enable_device() calls pci_set_power_state(dev, PCI_D0) as the first
> >> >>>>>> thing. The question is why it doesn't work as expected.
> >> >>>>> not sure... please check the version for forcedeth that you made.
> >> >>>>>
> >> >>>>> commit 3cb5599a84c557c0dd9a19feb63a3788268cf249
> >> >>>>> Author: Rafael J. Wysocki <rjw@xxxxxxx>
> >> >>>>> Date: Fri Sep 5 14:00:19 2008 -0700
> >> >>>>>
> >> >>>>> forcedeth: fix kexec regression
> >> >>>>>
> >> >>>>> Fix regression tracked as http://bugzilla.kernel.org/show_bug.cgi?id=11361
> >> >>>>> and caused by commit f735a2a1a4f2a0f5cd823ce323e82675990469e2 ("[netdrvr]
> >> >>>>> forcedeth: setup wake-on-lan before shutting down") that makes network
> >> >>>>> adapters integrated into the NVidia MCP55 chipsets fail to work in kexeced
> >> >>>>> kernels. The problem appears to be that if the adapter is put into D3_hot
> >> >>>>> during ->shutdown(), it cannot be brought back into D0 after kexec (ref.
> >> >>>>> http://marc.info/?l=linux-kernel&m=121900062814967&w=4). Therefore, only
> >> >>>>> put forcedeth into D3 during ->shutdown() if the system is to be powered
> >> >>>>> off.
> >> >>>> Thanks, I remember now.
> >> >>> In which case you need to rework igb_shutdown() rather than igb_suspend().
> >> >>>
> >> >>> Something like the patch below, perhaps (totally untested).
> >> >> it works, David, can you picked it up
> >> >
> >> > Still, Yinghai, can you please also test the patch below? It fixes all
> >> > shortcomings in the driver's suspend and shutdown methods I was talking about
> >> > in one of the previous messages. If it works, IMO it will be a preferable fix
> >> > (in particular, it would be good to check if WoL still works with it,
> >> > but I don't have the hardware).
> >> >
> >> > Thanks,
> >> > Rafael
> >> >
> >> > ---
> >> > From: Rafael J. Wysocki <rjw@xxxxxxx>
> >> > Subject: net/igb: Fix kexec with igb (rev. 3)
> >> > Impact: Fix
> >> >
> >> > Yinghai Lu found one system with 82575EB where, in the kernel that is
> >> > kexeced, probe igb failed with -2, the reason being that the adapter
> >> > could not be brought back from D3 by the kexec kernel, most probably
> >> > due to quirky hardware (it looks like the same behavior happened on
> >> > forcedeth).
> >> >
> >> > Prevent igb from putting the adapter into D3 during shutdown except
> >> > when we going to power off the system. For this purpose, seperate
> >> > igb_shutdown() from igb_suspend() and use the appropriate PCI PM
> >> > callbacks in both of them.
> >> >
> >> > Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
> >> > Reported-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> >> > ---
> >> > drivers/net/igb/igb_main.c | 42 ++++++++++++++++++++++++++++++------------
> >> > 1 file changed, 30 insertions(+), 12 deletions(-)
> >> >
> >> > Index: linux-2.6/drivers/net/igb/igb_main.c
> >> > ===================================================================
> >> > --- linux-2.6.orig/drivers/net/igb/igb_main.c
> >> > +++ linux-2.6/drivers/net/igb/igb_main.c
> >> > @@ -4277,7 +4277,7 @@ int igb_set_spd_dplx(struct igb_adapter
> >> > }
> >> >
> >> >
> >> > -static int igb_suspend(struct pci_dev *pdev, pm_message_t state)
> >> > +static int __igb_shutdown(struct pci_dev *pdev, bool *enable_wake)
> >> > {
> >> > struct net_device *netdev = pci_get_drvdata(pdev);
> >> > struct igb_adapter *adapter = netdev_priv(netdev);
> >> > @@ -4336,15 +4336,9 @@ static int igb_suspend(struct pci_dev *p
> >> > wr32(E1000_WUFC, 0);
> >> > }
> >> >
> >> > - /* make sure adapter isn't asleep if manageability/wol is enabled */
> >> > - if (wufc || adapter->en_mng_pt) {
> >> > - pci_enable_wake(pdev, PCI_D3hot, 1);
> >> > - pci_enable_wake(pdev, PCI_D3cold, 1);
> >> > - } else {
> >> > + *enable_wake = wufc || adapter->en_mng_pt;
> >> > + if (!*enable_wake)
> >> > igb_shutdown_fiber_serdes_link_82575(hw);
> >> > - pci_enable_wake(pdev, PCI_D3hot, 0);
> >> > - pci_enable_wake(pdev, PCI_D3cold, 0);
> >> > - }
> >> >
> >> > /* Release control of h/w to f/w. If f/w is AMT enabled, this
> >> > * would have already happened in close and is redundant. */
> >> > @@ -4352,12 +4346,29 @@ static int igb_suspend(struct pci_dev *p
> >> >
> >> > pci_disable_device(pdev);
> >> >
> >> > - pci_set_power_state(pdev, pci_choose_state(pdev, state));
> >> > -
> >> > return 0;
> >> > }
> >> >
> >> > #ifdef CONFIG_PM
> >> > +static int igb_suspend(struct pci_dev *pdev, pm_message_t state)
> >> > +{
> >> > + int retval;
> >> > + bool wake;
> >> > +
> >> > + retval = __igb_shutdown(pdev, &wake);
> >> > + if (retval)
> >> > + return retval;
> >> > +
> >> > + if (wake) {
> >> > + pci_prepare_to_sleep(pdev);
> >> > + } else {
> >> > + pci_wake_from_d3(pdev, false);
> >> > + pci_set_power_state(pdev, PCI_D3hot);
> >> > + }
> >> > +
> >> > + return 0;
> >> > +}
> >> > +
> >> > static int igb_resume(struct pci_dev *pdev)
> >> > {
> >> > struct net_device *netdev = pci_get_drvdata(pdev);
> >> > @@ -4412,7 +4423,14 @@ static int igb_resume(struct pci_dev *pd
> >> >
> >> > static void igb_shutdown(struct pci_dev *pdev)
> >> > {
> >> > - igb_suspend(pdev, PMSG_SUSPEND);
> >> > + bool wake;
> >> > +
> >> > + __igb_shutdown(pdev, &wake);
> >> > +
> >> > + if (system_state == SYSTEM_POWER_OFF) {
> >> > + pci_wake_from_d3(pdev, wake);
> >> > + pci_set_power_state(pdev, PCI_D3hot);
> >> > + }
> >> > }
> >> >
> >> > #ifdef CONFIG_NET_POLL_CONTROLLER
> >>
> >> it works too.
> >
> > Great, thanks for testing.
> >
> > Jeff, Jesse, is the patch fine with you?
> >
> > Rafael
>
> Let me talk with Jesse on Monday about it. I know that Jesse's
> concern's were that there were more than one driver afflicted with the
> same or similar issue and that it made more sense to fix this in the
> core for all drivers. For instance ixgbe, IIRC, but because Yinghai
> did not have any other hardware, it was unclear if this was an issue
> on other drivers.
I think it was, at least theoretically. We should generally avoid powering
off things on shutdown when it's not really necessary. Also, the use of
pci_enable_wake() in these drivers is not really correct.
And in fact this is why I'm asking, because I have analogouns patches for some
other drivers in the works too. If you are fine with the approach, I'll post
the whole series.
> After discussing this with Jesse, one of us will respond. I will
> apply this patch to my tree anyway and if we are alright with the
> patch, I will push it out with my other patches to Dave.
Thanks!
Best,
Rafael
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