diff options
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 59 |
1 files changed, 55 insertions, 4 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 1b34fc56067..65ea7d25f69 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -222,6 +222,37 @@ pci_find_parent_resource(const struct pci_dev *dev, struct resource *res) } /** + * pci_restore_bars - restore a devices BAR values (e.g. after wake-up) + * @dev: PCI device to have its BARs restored + * + * Restore the BAR values for a given device, so as to make it + * accessible by its driver. + */ +void +pci_restore_bars(struct pci_dev *dev) +{ + int i, numres; + + switch (dev->hdr_type) { + case PCI_HEADER_TYPE_NORMAL: + numres = 6; + break; + case PCI_HEADER_TYPE_BRIDGE: + numres = 2; + break; + case PCI_HEADER_TYPE_CARDBUS: + numres = 1; + break; + default: + /* Should never get here, but just in case... */ + return; + } + + for (i = 0; i < numres; i ++) + pci_update_resource(dev, &dev->resource[i], i); +} + +/** * pci_set_power_state - Set the power state of a PCI device * @dev: PCI device to be suspended * @state: PCI power state (D0, D1, D2, D3hot, D3cold) we're entering @@ -239,7 +270,7 @@ int (*platform_pci_set_power_state)(struct pci_dev *dev, pci_power_t t); int pci_set_power_state(struct pci_dev *dev, pci_power_t state) { - int pm; + int pm, need_restore = 0; u16 pmcsr, pmc; /* bound the state we're entering */ @@ -278,14 +309,17 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state) return -EIO; } + pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr); + /* If we're in D3, force entire word to 0. * This doesn't affect PME_Status, disables PME_En, and * sets PowerState to 0. */ - if (dev->current_state >= PCI_D3hot) + if (dev->current_state >= PCI_D3hot) { + if (!(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) + need_restore = 1; pmcsr = 0; - else { - pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr); + } else { pmcsr &= ~PCI_PM_CTRL_STATE_MASK; pmcsr |= state; } @@ -308,6 +342,22 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state) platform_pci_set_power_state(dev, state); dev->current_state = state; + + /* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT + * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning + * from D3hot to D0 _may_ perform an internal reset, thereby + * going to "D0 Uninitialized" rather than "D0 Initialized". + * For example, at least some versions of the 3c905B and the + * 3c556B exhibit this behaviour. + * + * At least some laptop BIOSen (e.g. the Thinkpad T21) leave + * devices in a D3hot state at boot. Consequently, we need to + * restore at least the BARs so that the device will be + * accessible to its driver. + */ + if (need_restore) + pci_restore_bars(dev); + return 0; } @@ -805,6 +855,7 @@ struct pci_dev *isa_bridge; EXPORT_SYMBOL(isa_bridge); #endif +EXPORT_SYMBOL_GPL(pci_restore_bars); EXPORT_SYMBOL(pci_enable_device_bars); EXPORT_SYMBOL(pci_enable_device); EXPORT_SYMBOL(pci_disable_device); |