Regression caused by commit bc976233a872, ethernet r8169 stops working after system S3

[Kai-Heng Feng]

Hi Thomas,

A user reported [1] that the Realtek ethernet r8169 stops working after S3  
since v4.15-rc6. The issue still exists in Linus' tree:

[ 150.877998] IPv6: ADDRCONF(NETDEV_UP): enp1s0: link is not ready
[ 150.944101] do_IRQ: 3.37 No irq handler for vector
[ 150.944105] r8169 0000:01:00.0 enp1s0: link down
[ 150.944180] IPv6: ADDRCONF(NETDEV_UP): enp1s0: link is not ready

My desktop also has this device, which is also affected by this regression.  
So I did a bisect, and this is the bad commit:
bc976233a872 genirq/msi x86/vector: Prevent reservation mode for non  
maskable MSI

After this commit gets reverted, the issue is gone.

Let me know if you need more debug information.

Kai-Heng

[1] https://bugs.launchpad.net/bugs/1752772