Re: [PATCH] igb: fix kexec with igb

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Monday 09 March 2009, Yinghai Lu wrote:
> On Sun, Mar 8, 2009 at 3:57 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > On Sunday 08 March 2009, Yinghai Lu wrote:
> >> On Sun, Mar 8, 2009 at 2:32 PM, Rafael J. Wysocki <rjw@sisk.pl> 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@gmail.com> wrote:
> >> >> > >>> On Fri, Mar 6, 2009 at 8:33 PM, Yinghai Lu <yinghai@kernel.org> 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@kernel.org>
> >> >> > >>>>
> >> >> > >>>> ---
> >> >> > >>>>  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@sisk.pl>
> >> >> > 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).
> >> >
> >> > Thanks,
> >> > Rafael
> >> >
> >> > ---
> >> >  drivers/net/igb/igb_main.c |   24 +++++++++++++++++++-----
> >> >  1 file changed, 19 insertions(+), 5 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
> >> > @@ -4299,7 +4299,7 @@ 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);
> >> > @@ -4359,7 +4359,7 @@ static int igb_suspend(struct pci_dev *p
> >> >        }
> >> >
> >> >        /* make sure adapter isn't asleep if manageability/wol is enabled */
> >> > -       if (wufc || adapter->en_mng_pt) {
> >> > +       if ((wufc || adapter->en_mng_pt) && enable_wake) {
> >> >                pci_enable_wake(pdev, PCI_D3hot, 1);
> >> >                pci_enable_wake(pdev, PCI_D3cold, 1);
> >> >        } else {
> >> > @@ -4374,12 +4374,21 @@ 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;
> >> > +
> >> > +       retval = __igb_shutdown(pdev, true);
> >> > +       if (!retval)
> >> > +               pci_set_power_state(pdev, PCI_D3hot);
> >> > +
> >> > +       return retval;
> >> > +}
> >> > +
> >> >  static int igb_resume(struct pci_dev *pdev)
> >> >  {
> >> >        struct net_device *netdev = pci_get_drvdata(pdev);
> >> > @@ -4434,7 +4443,12 @@ static int igb_resume(struct pci_dev *pd
> >> >
> >> >  static void igb_shutdown(struct pci_dev *pdev)
> >> >  {
> >> > -       igb_suspend(pdev, PMSG_SUSPEND);
> >> > +       if (system_state == SYSTEM_POWER_OFF) {
> >> > +               __igb_shutdown(pdev, true);
> >> > +               pci_set_power_state(pdev, PCI_D3hot);
> >>
> >> you don't need to use pci_choose_state(pdev, state), but use PCI-D3hot directly?
> >
> > Yes, because we've already decided we'd put the device into D3_hot by calling
> > pci_enable_wake(pdev, PCI_D3hot, 1) in __igb_shutdown().
> >
> > In fact we should first determine the target state and _then_ call
> > pci_enable_wake() and pci_set_power_state() with that as the argument, but this
> > is a separate issue.  For now, IMO, it's better to use D3_hot in both places
> > directly.
> >
> > On a slightly related note, the sequence
> >
> >                pci_enable_wake(pdev, PCI_D3hot, 1);
> >                pci_enable_wake(pdev, PCI_D3cold, 1);
> >
> > is (slightly) incorrect by itself, because ACPI doesn't distinguish bewteen
> > D3_hot and D3_cold, so this just causes the same platform code to run twice,
> > which may or may not work (it theory it should always work, but still).
> >
> > This is yet another problem, though.
> 
> can you go through e1000, e1000e, ixgb, ixgbe too?

OK, I will, but it's going to take some time.

Thanks,
Rafael