Add pci_pr3_present() to check whether the platform supplies _PR3 to tell us which power resources the device depends on when in D3hot. This information is useful to let drivers choose different runtime suspend behavior. A user will be add in next patch.
This is mostly the same as nouveau_pr3_present().
Signed-off-by: Kai-Heng Feng kai.heng.feng@canonical.com --- v5: - Add wording suggestion from Bjorn. v4: - Let caller to find its upstream port device.
drivers/pci/pci.c | 16 ++++++++++++++++ include/linux/pci.h | 2 ++ 2 files changed, 18 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e7982af9a5d8..d03f624d8928 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5856,6 +5856,22 @@ int pci_set_vga_state(struct pci_dev *dev, bool decode, return 0; }
+bool pci_pr3_present(struct pci_dev *pdev) +{ + struct acpi_device *adev; + + if (acpi_disabled) + return false; + + adev = ACPI_COMPANION(&pdev->dev); + if (!adev) + return false; + + return adev->power.flags.power_resources && + acpi_has_method(adev->handle, "_PR3"); +} +EXPORT_SYMBOL_GPL(pci_pr3_present); + /** * pci_add_dma_alias - Add a DMA devfn alias for a device * @dev: the PCI device for which alias is added diff --git a/include/linux/pci.h b/include/linux/pci.h index f9088c89a534..1d15c5d49cdd 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -2310,9 +2310,11 @@ struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus);
void pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *)); +bool pci_pr3_present(struct pci_dev *pdev); #else static inline struct irq_domain * pci_host_bridge_acpi_msi_domain(struct pci_bus *bus) { return NULL; } +static bool pci_pr3_present(struct pci_dev *pdev) { return false; } #endif
#ifdef CONFIG_EEH