From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
The part of pci_set_power_state() related to transitions into
low-power states is unnecessary convoluted, so clearly divide it
into the D3cold special case and the general case covering all of
the other states.
Also fix a potential issue with calling pci_bus_set_current_state()
to set the current state of all devices on the subordinate to D3cold
without checking if the power state of the parent bridge has really
changed to D3cold.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
v1 -> v2: No changes.
---
drivers/pci/pci.c | 28 +++++++++++++++++-----------
1 file changed, 17 insertions(+), 11 deletions(-)
Index: linux-pm/drivers/pci/pci.c
===================================================================
--- linux-pm.orig/drivers/pci/pci.c
+++ linux-pm/drivers/pci/pci.c
@@ -1431,19 +1431,25 @@ int pci_set_power_state(struct pci_dev *
if (state >= PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
return 0;
- /*
- * To put device in D3cold, we put device into D3hot in native
- * way, then put device into D3cold with platform ops
- */
- error = pci_set_low_power_state(dev, state > PCI_D3hot ?
- PCI_D3hot : state);
+ if (state == PCI_D3cold) {
+ /*
+ * To put the device in D3cold, put it into D3hot in the native
+ * way, then put it into D3cold using platform ops.
+ */
+ error = pci_set_low_power_state(dev, PCI_D3hot);
- if (pci_platform_power_transition(dev, state))
- return error;
+ if (pci_platform_power_transition(dev, PCI_D3cold))
+ return error;
- /* Powering off a bridge may power off the whole hierarchy */
- if (state == PCI_D3cold)
- pci_bus_set_current_state(dev->subordinate, PCI_D3cold);
+ /* Powering off a bridge may power off the whole hierarchy */
+ if (dev->current_state == PCI_D3cold)
+ pci_bus_set_current_state(dev->subordinate, PCI_D3cold);
+ } else {
+ error = pci_set_low_power_state(dev, state);
+
+ if (pci_platform_power_transition(dev, state))
+ return error;
+ }
return 0;
}
