Commit 5839ee73 authored Dec 15, 2017 by Rafael J. Wysocki

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: e60514bd (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>

parent 1291a0d5

drivers/pci/pci-driver.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -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)

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