Commit 42eca230 authored Oct 29, 2012 by Dave Airlie Committed by Bjorn Helgaas Nov 07, 2012

PCI: Don't touch card regs after runtime suspend D3



If the driver takes care of state saving, don't touch any registers on it.

Optimus (dual-gpu) laptops seem to have their own form of D3cold, but
unfortunately enter it on normal D3 transitions via the ACPI callback.

So when we use runtime PM to transition to D3, the card disappears off
the PCI bus, however we then try to access registers on it in the
runtime suspend finish, which really doesn't work.

This patch checks whether the pci state is saved and doesn't attempt to hit
any registers after that point if it is.

(Looks okay to Rafael)

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

parent 8f0d8163

drivers/pci/pci-driver.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -1023,10 +1023,10 @@ static int pci_pm_runtime_suspend(struct device *dev)
		return 0;
		}

		if (!pci_dev->state_saved)
		if (!pci_dev->state_saved) {
		pci_save_state(pci_dev);

		pci_finish_runtime_suspend(pci_dev);
		}

		return 0;
		}

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