From: Rafael J. Wysocki <rjw@xxxxxxx> 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. Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> --- drivers/pci/pci.c | 2 ++ 1 file changed, 2 insertions(+) Index: linux-2.6/drivers/pci/pci.c =================================================================== --- linux-2.6.orig/drivers/pci/pci.c +++ linux-2.6/drivers/pci/pci.c @@ -480,6 +480,8 @@ static int pci_raw_set_power_state(struc 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)) _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
