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Message-Id: <200808172347.36582.rjw@sisk.pl>
Date: Sun, 17 Aug 2008 23:47:35 +0200
From: "Rafael J. Wysocki" <rjw@...k.pl>
To: "Yinghai Lu" <yhlu.kernel@...il.com>
Cc: "Jeff Garzik" <jgarzik@...hat.com>, "Ingo Molnar" <mingo@...e.hu>,
"Eric W. Biederman" <ebiederm@...ssion.com>,
"Andrew Morton" <akpm@...ux-foundation.org>,
linux-kernel@...r.kernel.org, netdev <netdev@...r.kernel.org>,
Jesse Barnes <jbarnes@...tuousgeek.org>
Subject: Re: [PATCH] net: forcedeth use pci_choose_state instead of PCI_D3hot - v2
On Sunday, 17 of August 2008, Yinghai Lu wrote:
> On Sun, Aug 17, 2008 at 12:34 PM, Rafael J. Wysocki <rjw@...k.pl> 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@...k.pl> 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@...edrich.de>
> >> > >> > | 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@...edrich.de>
> >> > >> > | Signed-off-by: Jeff Garzik <jgarzik@...hat.com>
> >> > >> >
> >> > >> > 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@...k.pl>
> >> > > ---
> >> > > 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.
Thanks,
Rafael
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