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>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 1a91bf9687af..761557688b18 100644
--- a/drivers/pci/pci.c
+++ b/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 |= state;
                 break;
+        case PCI_D3hot:
+        case PCI_D3cold:
         case PCI_UNKNOWN: /* Boot-up */
                 if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
                  && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))