[SRU] [A/B/linux-oem] [PATCH 0/7] Fix Runtime PM for r8169

[Kai-Heng Feng]

BugLink: https://bugs.launchpad.net/bugs/1757422

[Impact]
r8169 stays in D0 even when no ethernet cable is plugged in. This drains
lots of power (~3W). The tested laptop uses 5.5W when r8169 is in D0,
1.8W when r8169 is in D3. The power saved is substantial.

[Fix]
Improved rumtime PM logic to let the device gets suspended (D3) when the
port is not in used and the link is down.

[Test Case]
The chip version is 8168h/8111h.
Test when no ethernet gets plugged.

Powertop shows power consumption is roughly 5.5W.
lspci shows the device is in D0.

With the patch,
The power consumption is reduced to 1.8W.
lspci shows the device is in D3, PME# is correctly enabled.
Plug ethernet cable can corretly wake up the device.
Unplug the cable, the device gets suspended to D3 correctly.

[Regression Potential]
Medium.
- r8169 is so ubiquitous, with lots of different chip versions. It's
  hard to test all of them.
- PCI D3 needs system firmware (ACPI) support, this might hit some
  plaform bugs.
- the code is still in v4.16-rc*, so it's not well tested by end users.

If it's too risky to merge this series into Artful, it should still get
merged for Bionic, the power consumption reduction is significant.

Daniel Drake (1):
  r8169: only enable PCI wakeups when WOL is active

Heiner Kallweit (6):
  PCI: Add pcim_set_mwi(), a device-managed pci_set_mwi()
  r8169: switch to device-managed functions in probe
  r8169: remove netif_napi_del in probe error path
  r8169: remove unneeded rpm ops in rtl_shutdown
  r8169: improve runtime pm in rtl8169_check_link_status
  r8169: improve runtime pm in general and suspend unused ports

 drivers/net/ethernet/realtek/r8169.c | 131 ++++++++++-------------------------
 drivers/pci/pci.c                    |  25 +++++++
 include/linux/pci.h                  |   1 +
 3 files changed, 62 insertions(+), 95 deletions(-)

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2.15.1