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

From: "Rafael J. Wysocki" <[email-masked]>
Date: Sun, 8 Mar 2009 22:32:35 +0100

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).

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);
+	} else {
+		__igb_shutdown(pdev, false);
+	}
 }
 
 #ifdef CONFIG_NET_POLL_CONTROLLER