[RFC,0/4] DP link training failure fallback

Message

Murthy, Arun R Feb. 6, 2024, 10:47 a.m. UTC

The series depicts a working skeleton of the fallback sequence in case
on DP link training failure.
The fallback is currently implemented for DP2.0 only, on similar basis
DP1.4 fallback will come up in the same patch series.
A hotplug event was trigerred in the existing fallback sequence. This
has been removed. On fallback only the link rate and the lane count is
changed for which user need not be notified.
As part of the fallback, the link rate and lane count has to be changed
and these parameters are in intel_crtc_state struct which is passed as
const. The same variables link_rate and lane_count is available in
intel_dp structure. It would be more meaningful to use these for the dp
link training and fallback as well.
As part of cleanup the lane_count in intel_crtc_state structure has to
be removed and the port_clock will have to be used only in crtc
configuration. These changes will be included in this patch series.

Arun R Murthy (4):
  drm/i915/display/dp: Add DP fallback on LT
  drm/i915/display/dp: Dont send hotplug event on LT failure
  drm/i915/dp: use link rate and lane count in intel_dp struct
  drm/i915/display/dp: On LT failure retry LT

 drivers/gpu/drm/i915/display/intel_cx0_phy.c  |  16 +--
 drivers/gpu/drm/i915/display/intel_ddi.c      |  31 ++++--
 .../drm/i915/display/intel_ddi_buf_trans.c    |   7 +-
 drivers/gpu/drm/i915/display/intel_dp.c       | 100 +++++++++++++++---
 drivers/gpu/drm/i915/display/intel_dp.h       |   2 +-
 .../drm/i915/display/intel_dp_link_training.c |  86 +++++++--------
 .../drm/i915/display/intel_dp_link_training.h |   2 +-
 drivers/gpu/drm/i915/display/intel_dp_mst.c   |  29 ++---
 8 files changed, 184 insertions(+), 89 deletions(-)