diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-05-05 21:14:24 +0300 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2022-05-05 22:19:49 +0300 |
| commit | 0ce74a3b9c5255f641842df3c4c14fa8ea049a5a (patch) | |
| tree | f29f6288d365dbb42feb170b353b252732a7fee5 /drivers/pci | |
| parent | e200904b275c63dae711fca542f5fb20d162eb26 (diff) | |
| download | linux-0ce74a3b9c5255f641842df3c4c14fa8ea049a5a.tar.xz | |
PCI/PM: Do not restore BARs if device is not in D0
Do not attempt to restore the device's BARs in
pci_set_full_power_state() if the actual current
power state of the device is not D0.
Link: https://lore.kernel.org/r/1849718.CQOukoFCf9@kreacher
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/pci.c | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 44dcc848ff84..3320453d2691 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1273,25 +1273,25 @@ static int pci_set_full_power_state(struct pci_dev *dev) pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK; - if (dev->current_state != PCI_D0) + 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)); - - /* - * 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 (ret > 0) + } 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. + */ pci_restore_bars(dev); + } if (dev->bus->self) pcie_aspm_pm_state_change(dev->bus->self); |