Subject: Re: [Updated patch] Re: [PATCH] igb: fix kexec with igb

From: "Rafael J. Wysocki" <[email-masked]>
Date: Sat, 28 Mar 2009 22:27:28 +0100

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
> >>>>>>> <[email-masked]> wrote:
> >>>>>>>> On Fri, Mar 6, 2009 at 8:33 PM, Yinghai Lu <[email-masked]> 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 <[email-masked]>
> >>>>>>>>>
> >>>>>>>>> ---
> >>>>>>>>>  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 <[email-masked]>
> >>>>> 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 <[email-masked]>
> > 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 <[email-masked]>
> > Reported-by: Yinghai Lu <[email-masked]>
> > ---
> >  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