Commit 42eca230 authored by Dave Airlie's avatar Dave Airlie Committed by Bjorn Helgaas

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: default avatarDave Airlie <airlied@redhat.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 8f0d8163
......@@ -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;
}
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment