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| author | Lukas Wunner <lukas@wunner.de> | 2016-09-18 05:39:20 +0200 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2016-09-28 18:46:51 +0200 |
| commit | cc7cc02bada84f0d707aa5b6d2ef8728a2e1f911 (patch) | |
| tree | f1d963b141e5d6fae283afa49e4841faeeedb6e8 /drivers/pci/pci.c | |
| parent | PCI: Afford direct-complete to devices with non-standard PM (diff) | |
| download | linux-cc7cc02bada84f0d707aa5b6d2ef8728a2e1f911.tar.xz linux-cc7cc02bada84f0d707aa5b6d2ef8728a2e1f911.zip | |
PCI: Query platform firmware for device power state
Usually the most accurate way to determine a PCI device's power state is to
read its PM Control & Status Register. There are two cases however when
this is not an option: If the device doesn't have the PM capability at
all, or if it is in D3cold (in which case its config space is
inaccessible).
In both cases, we can alternatively query the platform firmware for its
opinion on the device's power state. To facilitate this, augment struct
pci_platform_pm_ops with a ->get_power callback and implement it for
acpi_pci_platform_pm (the only pci_platform_pm_ops existing so far).
It is used by a forthcoming commit to let pci_update_current_state()
recognize D3cold.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 2f818c3e6571..2e18e9adcc15 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -552,8 +552,9 @@ static const struct pci_platform_pm_ops *pci_platform_pm; int pci_set_platform_pm(const struct pci_platform_pm_ops *ops) { - if (!ops->is_manageable || !ops->set_state || !ops->choose_state || - !ops->sleep_wake || !ops->run_wake || !ops->need_resume) + if (!ops->is_manageable || !ops->set_state || !ops->get_state || + !ops->choose_state || !ops->sleep_wake || !ops->run_wake || + !ops->need_resume) return -EINVAL; pci_platform_pm = ops; return 0; @@ -570,6 +571,11 @@ static inline int platform_pci_set_power_state(struct pci_dev *dev, return pci_platform_pm ? pci_platform_pm->set_state(dev, t) : -ENOSYS; } +static inline pci_power_t platform_pci_get_power_state(struct pci_dev *dev) +{ + return pci_platform_pm ? pci_platform_pm->get_state(dev) : PCI_UNKNOWN; +} + static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev) { return pci_platform_pm ? |