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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>
hifive-unleashed-5.1
Dave Airlie 2012-10-29 17:26:54 -06:00 committed by Bjorn Helgaas
parent 8f0d8163b5
commit 42eca23021
1 changed files with 3 additions and 3 deletions
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6
drivers/pci/pci-driver.c
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@ -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);
pci_finish_runtime_suspend(pci_dev);
}
return 0;
}