Commit a91a151f authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Greg Kroah-Hartman

PCI/PM: Fix fallback to PCI_D0 in pci_platform_power_transition()

commit 769ba721 upstream.

Commit b51306c6 (PCI: Set device power state to PCI_D0 for device
without native PM support) modified pci_platform_power_transition()
by adding code causing dev->current_state for devices that don't
support native PCI PM but are power-manageable by the platform to be
changed to PCI_D0 regardless of the value returned by the preceding
platform_pci_set_power_state().  In particular, that also is done
if the platform_pci_set_power_state() has been successful, which
causes the correct power state of the device set by
pci_update_current_state() in that case to be overwritten by PCI_D0.

Fix that mistake by making the fallback to PCI_D0 only happen if
the platform_pci_set_power_state() has returned an error.

[bhelgaas: folded in Yinghai's simplification, added URL & stable info]
Reference: http://lkml.kernel.org/r/27806FC4E5928A408B78E88BBC67A2306F466BBA@ORSMSX101.amr.corp.intel.comReported-by: default avatarChris J. Benenati <chris.j.benenati@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Acked-by: default avatarYinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent aebbd5d3
...@@ -646,15 +646,11 @@ static int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state) ...@@ -646,15 +646,11 @@ static int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
error = platform_pci_set_power_state(dev, state); error = platform_pci_set_power_state(dev, state);
if (!error) if (!error)
pci_update_current_state(dev, state); pci_update_current_state(dev, state);
/* Fall back to PCI_D0 if native PM is not supported */ } else
if (!dev->pm_cap)
dev->current_state = PCI_D0;
} else {
error = -ENODEV; error = -ENODEV;
/* Fall back to PCI_D0 if native PM is not supported */
if (!dev->pm_cap) if (error && !dev->pm_cap) /* Fall back to PCI_D0 */
dev->current_state = PCI_D0; dev->current_state = PCI_D0;
}
return error; return error;
} }
......
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