We need to be able to do cross-transport key derivation in LE -> BR/EDR and BR/EDR -> LE directions. The latter requires SMP over BR/EDR support (SMP over a BR/EDR fixed L2CAP channel). For testing & implementation purposes (when a controller supporting BR/EDR SC isn't available) there should be some way to temporarily switch off the requirement of having a BR/EDR SC connection. Linux has a "force_bredr_smp" debugfs file that you'll need to use to switch off the requirement on that side.
Reported by Johan Hedberg:
We need to be able to do cross-transport key derivation in LE -> BR/EDR and BR/EDR -> LE directions. The latter requires SMP over BR/EDR support (SMP over a BR/EDR fixed L2CAP channel). For testing & implementation purposes (when a controller supporting BR/EDR SC isn't available) there should be some way to temporarily switch off the requirement of having a BR/EDR SC connection. Linux has a "force_bredr_smp" debugfs file that you'll need to use to switch off the requirement on that side.
(Imported from Jira ZEP-605)