[PATCH 3.16 71/99] igb: Fix an issue that PME is not enabled during runtime suspend

[Ben Hutchings]

3.16.65-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>

commit 1fb3a7a75e2efcc83ef21f2434069cddd6fae6f5 upstream.

I210 ethernet card doesn't wakeup when a cable gets plugged. It's
because its PME is not set.

Since commit 42eca2302146 ("PCI: Don't touch card regs after runtime
suspend D3"), if the PCI state is saved, pci_pm_runtime_suspend() stops
calling pci_finish_runtime_suspend(), which enables the PCI PME.

To fix the issue, let's not to save PCI states when it's runtime
suspend, to let the PCI subsystem enables PME.

Fixes: 42eca2302146 ("PCI: Don't touch card regs after runtime suspend D3")
Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
Tested-by: Aaron Brown <aaron.f.brown@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/intel/igb/igb_main.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -7419,9 +7419,11 @@ static int __igb_shutdown(struct pci_dev
 	igb_clear_interrupt_scheme(adapter);
 
 #ifdef CONFIG_PM
-	retval = pci_save_state(pdev);
-	if (retval)
-		return retval;
+	if (!runtime) {
+		retval = pci_save_state(pdev);
+		if (retval)
+			return retval;
+	}
 #endif
 
 	status = rd32(E1000_STATUS);