Hi!
> From: Rafael J. Wysocki <rjw@xxxxxxx>
>
> The new suspend and hibernation callbacks introduced with
> 'struct pm_ops' and 'struct pm_ext_ops' do not take a
> pm_message_t argument, so the drivers using them will not be able
> to use pci_choose_state() in its present form. For this reason,
> introduce a new function, pci_choose_and_set_state(), playing the
> role of pci_choose_state() combined with pci_set_power_state() and
> allowing the driver to put the device into a power state chosen by
> the platform.
>
> Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
> ---
> drivers/pci/pci.c | 46 +++++++++++++++++++++++++++++++++++++++++++++-
> include/linux/pci.h | 1 +
> 2 files changed, 46 insertions(+), 1 deletion(-)
>
> Index: linux-2.6/drivers/pci/pci.c
> ===================================================================
> --- linux-2.6.orig/drivers/pci/pci.c
> +++ linux-2.6/drivers/pci/pci.c
> @@ -509,7 +509,51 @@ pci_set_power_state(struct pci_dev *dev,
> }
>
> pci_power_t (*platform_pci_choose_state)(struct pci_dev *dev);
> -
> +
> +/**
> + * pci_choose_and_set_state - Choose the power state of a PCI device and put
> + * the device into that state.
> + * @dev: PCI device to be put into a low power state
> + * @state: State to put the device into by default
> + *
> + * Use the platform driver to choose the preferred PCI power state of given
> + * device and put the device into that state. If the target power state of
> + * the device cannot be chosen using the platform driver, the driver-provided
> + * @state is used.
> + *
> + * RETURN VALUE:
> + * -EINVAL if trying to enter a lower state than we're already in.
> + * 0 if we're already in the requested state.
> + * -EIO if device does not support PCI PM.
> + * 0 if we can successfully change the power state.
> + */
> +
> +int pci_choose_and_set_state(struct pci_dev *dev, pci_power_t state)
> +{
> + if (!pci_find_capability(dev, PCI_CAP_ID_PM))
> + return -EIO;
Hmm, not sure if this is good idea. First, simple drivers will just
ignore the return value, and second, it returns -EIO even if I'm
asking it to enter state it already has -- like PCI_D0 -- no?
> + if (platform_pci_choose_state) {
> + pci_power_t ret = platform_pci_choose_state(dev);
> +
> + switch (ret) {
> + case PCI_POWER_ERROR:
> + case PCI_UNKNOWN:
> + break;
> + case PCI_D1:
> + case PCI_D2:
> + if (pci_no_d1d2(dev))
> + break;
> + default:
> + state = ret;
> + }
> + }
> +
> + return pci_set_power_state(dev, state);
> +}
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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