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

Lin Ming
2012-04-16T00:48:31Z

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.

Thanks,
Lin Ming