Subject: Re: [PATCH] e1000: the power down when running ifdown command

From: Dan Williams <[email-masked]>
Date: Mon, 02 Nov 2009 16:56:33 -0800

On Mon, 2009-11-02 at 16:26 -0800, Jeff Kirsher wrote:
> 2009/10/31 Naohiro Ooiwa <[email-masked]>:
> > Hi All
> >
> > I resend my patch.
> > Sorry, my previous mail lacked an explanation.
> >
> >
> > The e1000 driver doesn't let the power down when running ifdown command.
> > So, I set to the D3hot state of a PCI device at the end of e1000_close().
> >
> > With this modification, e1000 driver reduces power by ifdown.
> > It's about 6 watts when I measured a total power of one server machine
> > in my environment.
> >
> > I tested this patch. The result is good enough to me.
> >
> > Could you please check my patch ?
> > If I should have other considerations, please tell me.
> >
> >
> > Thanks you.
> > Naohiro Ooiwa
> >
> >
> >
> > Signed-off-by: Naohiro Ooiwa <[email-masked]>
> > ---
> >  drivers/net/e1000/e1000_main.c |   32 ++++++++++++++++++++++++++++++++
> >  1 files changed, 32 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
> > index bcd192c..12e1a42 100644
> > --- a/drivers/net/e1000/e1000_main.c
> > +++ b/drivers/net/e1000/e1000_main.c
> > @@ -26,6 +26,11 @@
> >
> >  *******************************************************************************/
> >
> > +/*
> > + * define this if you want pci save power while ifdown.
> > + */
> > +#define E1000_PCI_POWER_SAVE
> > +
> >  #include "e1000.h"
> >  #include <net/ip6_checksum.h>
> >
> > @@ -1248,6 +1253,23 @@ static int e1000_open(struct net_device *netdev)
> >        struct e1000_hw *hw = &adapter->hw;
> >        int err;
> >
> > +#ifdef E1000_PCI_POWER_SAVE
> > +       struct pci_dev *pdev = adapter->pdev;
> > +
> > +       pci_set_power_state(pdev, PCI_D0);
> > +       pci_restore_state(pdev);
> > +
> > +       if (adapter->need_ioport)
> > +               err = pci_enable_device(pdev);
> > +       else
> > +               err = pci_enable_device_mem(pdev);
> > +       if (err) {
> > +               printk(KERN_ERR "e1000: Cannot enable PCI device from power-save\n");
> > +               return err;
> > +       }
> > +       pci_set_master(pdev);
> > +#endif
> > +
> >        /* disallow open during test */
> >        if (test_bit(__E1000_TESTING, &adapter->flags))
> >                return -EBUSY;
> > @@ -1265,6 +1287,7 @@ static int e1000_open(struct net_device *netdev)
> >                goto err_setup_rx;
> >
> >        e1000_power_up_phy(adapter);
> > +       e1000_reset(adapter);
> >
> >        adapter->mng_vlan_id = E1000_MNG_VLAN_NONE;
> >        if ((hw->mng_cookie.status &
> > @@ -1341,6 +1364,15 @@ static int e1000_close(struct net_device *netdev)
> >                e1000_vlan_rx_kill_vid(netdev, adapter->mng_vlan_id);
> >        }
> >
> > +#ifdef E1000_PCI_POWER_SAVE
> > +#ifdef CONFIG_PM
> > +       pci_save_state(adapter->pdev);
> > +#endif
> > +       pci_disable_device(adapter->pdev);
> > +       pci_wake_from_d3(adapter->pdev, true);
> > +       pci_set_power_state(adapter->pdev, PCI_D3hot);
> > +#endif
> > +
> >        return 0;
> >  }
> >
> 
> I have added this patch to my tree for testing.  This patch requires a
> fair amount of regression testing, so once its passed testing I will
> push the patch to David/netdev.

Can we get rid of E1000_PCI_POWER_SAVE and just enable this
unconditionally once it's baked?  Having the define there is pretty
superfluous right now.  Either that, or make it
CONFIG_E1000_PCI_POWER_SAVE and make a Kconfig option for it that
depends on experimental or something.  Or a module parameter.  Or
something other than a dangling #define :)

Dan

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