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authorRafael J. Wysocki <rjw@sisk.pl>2009-01-07 07:07:15 -0500
committerJesse Barnes <jbarnes@virtuousgeek.org>2009-01-07 14:16:05 -0500
commit734104292ff77dc71fe626b4ebd91b314547ca1b (patch)
tree8e859beaa5065db26c7dc0d5e7a6a108c6f21163 /drivers/pci/pci.c
parent07e836e8d1f3688311d97fe1bf46980b0f9ae9c1 (diff)
PCI PM: Avoid touching devices behind bridges in unknown state
It generally is better to avoid accessing devices behind bridges that may not be in the D0 power state, because in that case the bridges' secondary buses may not be accessible. For this reason, during the early phase of resume (ie. with interrupts disabled), before restoring the standard config registers of a device, check the power state of the bridge the device is behind and postpone the restoration of the device's config space, as well as any other operations that would involve accessing the device, if that state is not D0. In such cases the restoration of the device's config space will be retried during the "normal" phase of resume (ie. with interrupts enabled), so that the bridge can be put into D0 before that happens. Also, save standard configuration registers of PCI devices during the "normal" phase of suspend (ie. with interrupts enabled), so that the bridges the devices are behind can be put into low power states (we don't put bridges into low power states at the moment, but we may want to do it in the future and it seems reasonable to design for that). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci/pci.c')
-rw-r--r--drivers/pci/pci.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 6e309c8b47df..e491fdedf705 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -527,7 +527,7 @@ pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
527 * @dev: PCI device to handle. 527 * @dev: PCI device to handle.
528 * @state: State to cache in case the device doesn't have the PM capability 528 * @state: State to cache in case the device doesn't have the PM capability
529 */ 529 */
530static void pci_update_current_state(struct pci_dev *dev, pci_power_t state) 530void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
531{ 531{
532 if (dev->pm_cap) { 532 if (dev->pm_cap) {
533 u16 pmcsr; 533 u16 pmcsr;