Browse Source

PCI PM: Follow PCI_PM_CTRL_NO_SOFT_RESET during transitions from D3

According to the PCI PM specification (PCI Bus Power Management
Interface Specification, Rev. 1.2, Section 5.4.1) we are supposed to
reinitialize devices that have PCI_PM_CTRL_NO_SOFT_RESET clear during
all transitions from PCI_D3hot to PCI_D0, but we only do it if the
device's current_state field is equal to PCI_UNKNOWN.

This may lead to problems if a device with PCI_PM_CTRL_NO_SOFT_RESET
unset is put into PCI_D3hot at run time by its driver and
pci_set_power_state() is used to put it back into PCI_D0, because in
that case the device will remain uninitialized after
pci_set_power_state() has returned.  Prevent that from happening by
modifying pci_raw_set_power_state() to reinitialize devices with
PCI_PM_CTRL_NO_SOFT_RESET unset during all transitions from D3 to D0.

Cc: stable@kernel.org
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Rafael J. Wysocki 16 years ago
parent
commit
f62795f1e8
1 changed files with 2 additions and 0 deletions
  1. 2 0
      drivers/pci/pci.c

+ 2 - 0
drivers/pci/pci.c

@@ -480,6 +480,8 @@ static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
 		pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
 		pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
 		pmcsr |= state;
 		pmcsr |= state;
 		break;
 		break;
+	case PCI_D3hot:
+	case PCI_D3cold:
 	case PCI_UNKNOWN: /* Boot-up */
 	case PCI_UNKNOWN: /* Boot-up */
 		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
 		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
 		 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
 		 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))