Messages in this thread Patch in this message | | | From | David Brownell <> | Subject | Re: [linux-pm] Adapt drivers to type-safe pci | Date | Mon, 1 Nov 2004 18:00:46 -0700 |
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On Monday 01 November 2004 12:26, Pavel Machek wrote: > Hi! > > This adapts few drivers to type-safe pci powermanagment. I introduced > device_to_pci_state helper that will be usefull to few drivers... Does > it look okay?
I'd rather have something like the attached patch. Fixed policy mappings are generically broken; what about devices that don't support PCI_D2?
This should I guess use the new "pci_power_t", but I'm not that current yet.
- Dave --- 1.73/drivers/pci/pci.c 2004-10-06 09:42:55 -07:00 +++ edited/drivers/pci/pci.c 2004-11-01 16:55:48 -08:00 @@ -229,7 +229,7 @@ /** * pci_set_power_state - Set the power state of a PCI device * @dev: PCI device to be suspended - * @state: Power state we're entering + * @state: PCI power state (D0, D1, D2, D3hot, D3cold) we're entering * * Transition a device to a new power state, using the Power Management * Capabilities in the device's config space. @@ -298,6 +298,54 @@ return 0; } + +/** + * pci_choose_state - Choose the power state of a PCI device + * @dev: PCI device to be suspended + * @state: target sleep state for the whole system + * + * If the device doesn't support PCI power management, this does nothing. + * Otherwise it puts the device in a PCI power state that it supports, + * and which for most devices is appropriate to that system sleep state. + * Some drivers will need to choose the PCI state themselves, calling + * pci_set_power_state() directly. + */ +void +pci_choose_state(struct pci_dev *pdev, suspend_state_t sleepstate) +{ + int pm, state; + u16 pmc; + + /* nothing to do for legacy PCI devices */ + pm = pci_find_capability(pdev, PCI_CAP_ID_PM); + if (!pm) + return; + + /* map to a PCI PM state this device supports + * FIXME ACPI may know what states to use; we should probably + * prefer that policy to this one. + */ + state = 3; + switch (sleepstate) { + case PM_SUSPEND_ON: + state = 0; + break; + case PM_SUSPEND_STANDBY: + case PM_SUSPEND_MEM: + pci_read_config_word(pdev, pm + PCI_PM_PMC, &pmc); + if (sleepstate == PM_SUSPEND_STANDBY + && (pmc & PCI_PM_CAP_D1) != 0) + state = 1; + else if ((pmc & PCI_PM_CAP_D2) != 0) + state = 2; + break; + } + + /* maybe go to a deeper power state */ + if (pdev->current_state < state) + pci_set_power_state(pdev, state); +} +EXPORT_SYMBOL(pci_choose_state); /** * pci_save_state - save the PCI configuration space of a device before suspending | |