diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 2127aba3550b5d611970bc8d3dccd7d5a60fa301..ff12a53a258158ba7c2f1eecdf65fdb7c2c79c38 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1199,24 +1199,23 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout) */ int pci_power_up(struct pci_dev *dev) { - bool need_restore; - pci_power_t state; + bool need_restore = false; u16 pmcsr; + int ret; - platform_pci_set_power_state(dev, PCI_D0); - - if (!dev->pm_cap) { - state = platform_pci_get_power_state(dev); - if (state == PCI_UNKNOWN) - dev->current_state = PCI_D0; - else - dev->current_state = state; + ret = platform_pci_set_power_state(dev, PCI_D0); + if (!ret) { + pci_update_current_state(dev, PCI_D0); + } else if (!dev->pm_cap) { /* Fall back to PCI_D0 */ + dev->current_state = PCI_D0; + return 0; + } - if (state == PCI_D0) - return 0; + if (dev->current_state == PCI_D0) + return 0; + if (!dev->pm_cap) return -EIO; - } pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); if (PCI_POSSIBLE_ERROR(pmcsr)) { @@ -1226,24 +1225,26 @@ int pci_power_up(struct pci_dev *dev) return -EIO; } - state = pmcsr & PCI_PM_CTRL_STATE_MASK; - - need_restore = (state == PCI_D3hot || dev->current_state >= PCI_D3hot) && - !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET); - - if (state == PCI_D0) - goto end; - /* * Force the entire word to 0. This doesn't affect PME_Status, disables * PME_En, and sets PowerState to 0. */ - pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, 0); + if (dev->current_state >= PCI_D3hot) { + if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot && + !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) + need_restore = true; + + pmcsr = 0; + } else { + pmcsr &= ~PCI_PM_CTRL_STATE_MASK; + } + + pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr); /* Mandatory transition delays; see PCI PM 1.2. */ - if (state == PCI_D3hot) + if (dev->current_state == PCI_D3hot) pci_dev_d3_sleep(dev); - else if (state == PCI_D2) + else if (dev->current_state == PCI_D2) udelay(PCI_PM_D2_DELAY); end: @@ -1280,20 +1281,21 @@ static int pci_set_full_power_state(struct pci_dev *dev) if (dev->current_state != PCI_D0) { pci_info_ratelimited(dev, "Refused to change power state from %s to D0\n", pci_power_name(dev->current_state)); - } else if (ret > 0) { - /* - * 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. - */ + + /* + * 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); }