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
