[PATCH 0/4] Implement Wa_14021768792 to bypass m_n ratio limit

[Ankit Nautiyal]

For Platforms that support higher link rates, there is a limitation on
Link M /Link N ratio.
If the CEILING( Link M / Link N ) ratio is greater than 10.0, then
hardware cannot support the given resolution / refresh rate at the given
configuration.
For BMG Wa_14021768792 helps to bypass this limitation and allows it to
support the ratio till 15.0.

This series adds the missing restrictions for earlier platforms and adds
the Wa_14021768792 for BMG as per Bspec:49266

Rev2:
-Drop new member link_n_extended.
-Avoid WA framework for XE

Rev3:
-Refactor to just add the extended link_n just before writing and scrub
it just after read.

Rev4:
-Prune modes for which the Link M/N ratio is more than the platform
limit.
-During Link configuration, for a given mode and link rate, check for
the Link M/N ratio, and choose higher link rate for which the ratio is
within the limits. (Ville)
-Use display WA framework.

Ankit Nautiyal (9):
  drm/i915: Add helper to compute link M/N ratio for reuse
  drm/i915/dp: Limit m/n ratio to 10 for DP SST
  drm/i915/dp_mst: Limit m/n ratio to 10 for MST
  drm/i915/dp: Add M/N ratio check with warning for DP link config
  drm/i915/display: Add bits for link_n_exended for DISPLAY >= 14
  drm/i915/display_wa: Add support for Wa_14021768792
  drm/i915/display: Add bits for Wa_14021768792 for linkm/n ratio > 10
  drm/i915/display: Implement Wa_14021768792 for BMG DP for link_m/n
    ratio > 10
  drm/i915/dp: Extend intel_dp_can_support_m_n() for BMG M/N bypass

 drivers/gpu/drm/i915/display/intel_display.c  | 143 ++++++++++++++++--
 drivers/gpu/drm/i915/display/intel_display.h  |   5 +
 .../gpu/drm/i915/display/intel_display_regs.h |   7 +
 .../drm/i915/display/intel_display_types.h    |   2 +
 .../gpu/drm/i915/display/intel_display_wa.c   |  18 +++
 .../gpu/drm/i915/display/intel_display_wa.h   |   1 +
 drivers/gpu/drm/i915/display/intel_dp.c       |  82 +++++++++-
 drivers/gpu/drm/i915/display/intel_dp.h       |   6 +
 drivers/gpu/drm/i915/display/intel_dp_mst.c   |  24 ++-
 drivers/gpu/drm/i915/display/intel_fdi.c      |   2 +
 10 files changed, 276 insertions(+), 14 deletions(-)

-- 
2.45.2