Certain (SGI?) ia64 boxes object to having their PCI BARs restored unless absolutely necessary. This patch restricts calling pci_restore_bars from pci_set_power_state unless the current state is PCI_UNKNOWN, the actual (i.e. physical) state of the device is PCI_D3hot, and the device indicates that it will lose its configuration when transitioning to PCI_D0. Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx> --- Many thanks to Keith Owens <kaos@xxxxxxx> for a) narrowing-down the problem; and, b) quickly testing the fix and reporting the results. drivers/pci/pci.c | 16 ++++++++++++---- 1 files changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -309,17 +309,25 @@ pci_set_power_state(struct pci_dev *dev, pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr); - /* If we're in D3, force entire word to 0. + /* If we're (effectively) in D3, force entire word to 0. * This doesn't affect PME_Status, disables PME_En, and * sets PowerState to 0. */ - if (dev->current_state >= PCI_D3hot) { - if (!(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) + switch (dev->current_state) { + case PCI_UNKNOWN: /* Boot-up */ + if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot + && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) need_restore = 1; + /* Fall-through: force to D0 */ + case PCI_D3hot: + case PCI_D3cold: + case PCI_POWER_ERROR: pmcsr = 0; - } else { + break; + default: pmcsr &= ~PCI_PM_CTRL_STATE_MASK; pmcsr |= state; + break; } /* enter specified state */