[PATCH v4 0/2][SRU][H] Fix the TGL-H system freeze problem after exiting s2idle

[chris.chiu at canonical.com]

From: Chris Chiu <chris.chiu at canonical.com>

BugLink: https://bugs.launchpad.net/bugs/1931072

[Impact]
The system will be hold by the infinite loop in ACPI method IPCS after exiting s2idle in TGL-H systems if the docking station with external display connected is unplugged when the system is still in s2idle. It's because the system is unaware of the unplug event and it seems keep something asserted which will never be released while the system trying to exit s2idle.

[Fix]
Disconnect TypeC PHYs during system suspend and shutdown, even with the
corresponding TypeC sink still plugged to its connector. The HPD event is no longer triggered when the system is in s2idle so the resume process will not be hindered.

[Test Case]
1. On all TigerLake-H and later platforms with NVIDIA GPU, make sure the NVIDIA GPU is running in either On-Demand mode or Performance mode.
2. Connect the docking station with the external display connected.
3. Suspend the system.
4. Remove the docking station when the system is suspended.
5. Press power button to wake up the system and wait > 1 minutes to make sure if the display comes back.

[Where problems could occur]
Low. This will only make a difference in the TypeC DP alternate mode, and the display driver will detect the display connector after resume.

V2: Fix the commit source of the 'backported'
V3: Add missing code of intel_ddi_encoder_suspend/shutdown
V4: Add additional patch for skl hpd pin mapping and explanation of
backport

Imre Deak (1):
  drm/i915: Force a TypeC PHY disconnect during suspend/shutdown

Lyude Paul (1):
  drm/i915/gen9_bc: Introduce HPD pin mappings for TGP PCH + CML combos

 drivers/gpu/drm/i915/display/intel_ddi.c | 44 ++++++++++++++++++++++--
 drivers/gpu/drm/i915/display/intel_tc.c  | 34 ++++++++++++++----
 drivers/gpu/drm/i915/display/intel_tc.h  |  2 ++
 3 files changed, 71 insertions(+), 9 deletions(-)

-- 
2.25.1