Re: [RFC PATCH] PCIe: Add PCIe runtime D3cold support

Rafael J. Wysocki
2012-04-16T16:22:18Z

On Monday, April 16, 2012, Lin Ming wrote:
> On Fri, 2012-04-13 at 21:41 +0200, Rafael J. Wysocki wrote:
> > Hi,
> >
> > On Friday, April 13, 2012, Yan, Zheng wrote:
> > > Hi all,
> > >
> > > This patch adds PCIe runtime D3cold support, namely cut power supply for functions
> > > beneath a PCIe port when they all have entered D3. A device in D3cold can only
> > > generate wake event through the WAKE# pin. Because we can not access to a device's
> > > configure space while it's in D3cold, pme_poll is disabled for devices in D3cold.
> > >
> > > Any comment will be appreciated.
> > >
> > > Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
> > > ---
> > > diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> > > index 0f150f2..e210e8cb 100644
> > > --- a/drivers/pci/pci-acpi.c
> > > +++ b/drivers/pci/pci-acpi.c
> > > @@ -224,7 +224,7 @@ static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
> > > [PCI_D1] = ACPI_STATE_D1,
> > > [PCI_D2] = ACPI_STATE_D2,
> > > [PCI_D3hot] = ACPI_STATE_D3,
> > > - [PCI_D3cold] = ACPI_STATE_D3
> > > + [PCI_D3cold] = ACPI_STATE_D3_COLD
> > > };
> > > int error = -EINVAL;
> > >
> >
> > Please don't use that ACPI_STATE_D3_COLD thing, it's not defined correctly.
> >
> > We should define ACPI_STATE_D3_COLD == ACPI_STATE_D3 and add ACPI_STATE_D3_HOT
> > instead. I'll prepare a patch for that over the weekend if no one has done
> > that already.
>
> Hi Rafael,
>
> Have you started to write the patch?
>
> If not, I can do it.

Please do if you have the time. I'd like this one to be cleaned up ASAP,
to reduce the amount of confusion taking place.

Thanks,
Rafael