Re: [PATCH] net: forcedeth use pci_choose_state instead of PCI_D3hot - v2

[Rafael J. Wysocki]

On Sunday, 17 of August 2008, Rafael J. Wysocki wrote:
> On Sunday, 17 of August 2008, Yinghai Lu wrote:
> > On Sun, Aug 17, 2008 at 12:34 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> > > On Sunday, 17 of August 2008, Rafael J. Wysocki wrote:
> > >> On Sunday, 17 of August 2008, Yinghai Lu wrote:
> > >> > On Sun, Aug 17, 2008 at 9:55 AM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> > >> > > On Sunday, 17 of August 2008, Rafael J. Wysocki wrote:
> > >> > >> On Sunday, 17 of August 2008, Yinghai Lu wrote:
> > >> > >> > after
> > >> > >> >
> > >> > >> > | commit f735a2a1a4f2a0f5cd823ce323e82675990469e2
> > >> > >> > | Author: Tobias Diedrich <ranma+kernel@xxxxxxxxxxxx>
> > >> > >> > | Date:   Sun May 18 15:02:37 2008 +0200
> > >> > >> > |
> > >> > >> > |    [netdrvr] forcedeth: setup wake-on-lan before shutting down
> > >> > >> > |
> > >> > >> > |    When hibernating in 'shutdown' mode, after saving the image the suspend hook
> > >> > >> > |    is not called again.
> > >> > >> > |    However, if the device is in promiscous mode, wake-on-lan will not work.
> > >> > >> > |    This adds a shutdown hook to setup wake-on-lan before the final shutdown.
> > >> > >> > |
> > >> > >> > |    Signed-off-by: Tobias Diedrich <ranma+kernel@xxxxxxxxxxxx>
> > >> > >> > |    Signed-off-by: Jeff Garzik <jgarzik@xxxxxxxxxx>
> > >> > >> >
> > >> > >> > my servers with nvidia mcp55 nic doesn't work with msi in second kernel by kexec
> > >> > >> >
> > >> > >> > after remove pci_set_power_state(, PCI_D3hot) that nic/msi will work again.
> > >> > >> >
> > >> > >> > check with e1000 is using pci_choose_state in _shutdown.
> > >> > >
> > >> > > This is wrong.
> > >> > >
> > >> > >> > So change that pci_choose_state(pdev, ...), and it works.
> > >> > >>
> > >> > >> Well, this doesn't look like a good solution to me, because you're putting
> > >> > >> PMSG_SUSPEND in there, which is not correct for shutdown.  The right thing to
> > >> > >> do would be to avoid changing the device power state if nv_shutdown() is
> > >> > >> used for kexec or to rework the initialization of the adapter to handle the
> > >> > >> case when it's initially in D3.
> > >> > >>
> > >> > >> Does it help if you just remove the pci_set_power_state(pdev, PCI_D3hot)
> > >> > >> altogether?
> > >> > >
> > >> > > Ah, sorry.  I see it does.
> > >> > >
> > >> > > Actually, I think you can use pci_prepare_to_sleep() instead of
> > >> > > pci_enable_wake() / pci_set_power_state() combo.  It wasn't designed for this
> > >> > > purpose, but should work nevertheless.
> > >> > >
> > >> > > Can you please check if the appended patch works instead of your one?
> > >> > >
> > >> > > Rafael
> > >> > >
> > >> > > ---
> > >> > > Fix the problem that boxes with NVidia MCP55 don't work with MSI
> > >> > > in a kexeced kernel.
> > >> > >
> > >> > > Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
> > >> > > ---
> > >> > >  drivers/net/forcedeth.c |    4 +---
> > >> > >  1 file changed, 1 insertion(+), 3 deletions(-)
> > >> > >
> > >> > > Index: linux-2.6/drivers/net/forcedeth.c
> > >> > > ===================================================================
> > >> > > --- linux-2.6.orig/drivers/net/forcedeth.c
> > >> > > +++ linux-2.6/drivers/net/forcedeth.c
> > >> > > @@ -5975,10 +5975,8 @@ static void nv_shutdown(struct pci_dev *
> > >> > >        if (netif_running(dev))
> > >> > >                nv_close(dev);
> > >> > >
> > >> > > -       pci_enable_wake(pdev, PCI_D3hot, np->wolenabled);
> > >> > > -       pci_enable_wake(pdev, PCI_D3cold, np->wolenabled);
> > >> > >        pci_disable_device(pdev);
> > >> > > -       pci_set_power_state(pdev, PCI_D3hot);
> > >> > > +       pci_prepare_to_sleep(pdev);
> > >> > >  }
> > >> > >  #else
> > >> > >  #define nv_suspend NULL
> > >> > >
> > >> > >
> > >> >
> > >> > your patch doesn't work...  it seems that silicon has problem with D3Hot
> > >>
> > >> Okay, so perhaps it's better to do something like this:
> > >>
> > >> ---
> > >>  drivers/net/forcedeth.c |    8 +++++---
> > >>  1 file changed, 5 insertions(+), 3 deletions(-)
> > >>
> > >> Index: linux-2.6/drivers/net/forcedeth.c
> > >> ===================================================================
> > >> --- linux-2.6.orig/drivers/net/forcedeth.c
> > >> +++ linux-2.6/drivers/net/forcedeth.c
> > >> @@ -5975,10 +5975,12 @@ static void nv_shutdown(struct pci_dev *
> > >>       if (netif_running(dev))
> > >>               nv_close(dev);
> > >>
> > >> -     pci_enable_wake(pdev, PCI_D3hot, np->wolenabled);
> > >> -     pci_enable_wake(pdev, PCI_D3cold, np->wolenabled);
> > >>       pci_disable_device(pdev);
> > >> -     pci_set_power_state(pdev, PCI_D3hot);
> > >> +     if (system_state == SYS_POWER_OFF) {
> > >
> > > Sorry, it should be SYSTEM_POWER_OFF here.  Corrected patch is appended.
> > >
> > >> +             if (pci_enable_wake(pdev, PCI_D3cold, np->wolenabled))
> > >> +                     pci_enable_wake(pdev, PCI_D3hot, np->wolenabled);
> > >> +             pci_set_power_state(pdev, PCI_D3hot);
> > >> +     }
> > >>  }
> > >>  #else
> > >>  #define nv_suspend NULL
> > >> --
> > >
> > > ---
> > >  drivers/net/forcedeth.c |    8 +++++---
> > >  1 file changed, 5 insertions(+), 3 deletions(-)
> > >
> > > Index: linux-2.6/drivers/net/forcedeth.c
> > > ===================================================================
> > > --- linux-2.6.orig/drivers/net/forcedeth.c
> > > +++ linux-2.6/drivers/net/forcedeth.c
> > > @@ -5975,10 +5975,12 @@ static void nv_shutdown(struct pci_dev *
> > >        if (netif_running(dev))
> > >                nv_close(dev);
> > >
> > > -       pci_enable_wake(pdev, PCI_D3hot, np->wolenabled);
> > > -       pci_enable_wake(pdev, PCI_D3cold, np->wolenabled);
> > >        pci_disable_device(pdev);
> > > -       pci_set_power_state(pdev, PCI_D3hot);
> > > +       if (system_state == SYSTEM_POWER_OFF) {
> > > +               if (pci_enable_wake(pdev, PCI_D3cold, np->wolenabled))
> > > +                       pci_enable_wake(pdev, PCI_D3hot, np->wolenabled);
> > > +               pci_set_power_state(pdev, PCI_D3hot);
> > > +       }
> > >  }
> > >  #else
> > >  #define nv_suspend NULL
> > >
> > 
> > why not like e1000 to
> > pci_set_power_state(pdev, pci_choose_state(pdev, PMSG_SUSPEND));
> > 
> > pci_choose_state would check if platform support those state...
> 
> ... but ->shutdown() only involves the platform in the
> 'system_state == SYSTEM_POWER_OFF' case!
> 
> In fact, using pci_choose_state() in ->shutdown() is a very convoluted way of
> checking the 'system_state' value, and not a 100% reliable one. :-)
> 
> Namely, the fact that pci_choose_state() returns you D0 instead of D3hot for
> 'system_state != SYSTEM_POWER_OFF' is a pure coincidence (accidentally, there
> is an ACPI handle for the device, but there need not be one) and you should
> not rely on that in general.  Generally speaking, pci_choose_state() is not to
> be used outside of the drivers' ->suspend() routines.
> 
> [Yes, this means e1000 will have to be fixed, as I said before.]
> 
> Apart from this, pci_choose_state() is broken and will shortly be deprecated.
> Moreover, in future all direct references to PMSG_SUSPEND from the drivers
> will be removed.

Does the last patch work for you BTW?

Rafael
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/