PCI / PM: Force devices to D0 in pci_pm_thaw_noirq()

It is incorrect to call pci_restore_state() for devices in low-power
states (D1-D3), as that involves the restoration of MSI setup which
requires MMIO to be operational and that is only the case in D0.

However, pci_pm_thaw_noirq() may do that if the driver's "freeze"
callbacks put the device into a low-power state, so fix it by making
it force devices into D0 via pci_set_power_state() instead of trying
to "update" their power state which is pointless.

Fixes: e60514bd4485 (PCI/PM: Restore the status of PCI devices across hibernation)
Cc: 4.13+ <stable@vger.kernel.org> # 4.13+
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Maarten Lankhorst <dev@mblankhorst.nl>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Maarten Lankhorst <dev@mblankhorst.nl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 945099d49f8f9b08c2b159d2cf4899b1fdc4cea4..14fd865a512096393149fd63a3707305648f276f 100644 (file)
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -1012,7 +1012,12 @@ static int pci_pm_thaw_noirq(struct device *dev)
        if (pci_has_legacy_pm_support(pci_dev))
                return pci_legacy_resume_early(dev);
 
-       pci_update_current_state(pci_dev, PCI_D0);
+       /*
+        * pci_restore_state() requires the device to be in D0 (because of MSI
+        * restoration among other things), so force it into D0 in case the
+        * driver's "freeze" callbacks put it into a low-power state directly.
+        */
+       pci_set_power_state(pci_dev, PCI_D0);
        pci_restore_state(pci_dev);
 
        if (drv && drv->pm && drv->pm->thaw_noirq)