drm/i915/dp_link_training: Disable failed config during fallback

Disable the link configuration that failed training when selecting
fallback parameters.

Fallback still selects the next configuration using the existing
fallback order, but now also removes the failed configuration from the
allowed set. Functionally, this only affects the case where an MST <-> SST
mode switch occurs on the same root connector: previously, a configuration
that failed training in one mode could be reused in the other mode due
to the differing config iteration orders.

The current fallback logic also sets a temporary maximum link limit
across the allowed configurations to constrain subsequent modesets. This
legacy behavior is preserved for now; it will be removed once the
fallback logic relies solely on the individually disabled configurations
to restrict the allowed set.

Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260701153204.4124150-26-imre.deak@intel.com

0 files changed, 0 insertions, 0 deletions