DF-4068 model: ti completion walks keyed on raw equality with NIC-DMA'd u32 index (if_ti.c:511,1629,1729)

rxeof/benign   ring=2048 prod_raw=0x00000025 -> TERMINATES after 37 iterations (consumer range [0,2047])
txeof/benign   ring=512  prod_raw=0x000001ff -> TERMINATES after 511 iterations (consumer range [0,511])
events/benign  ring=256  prod_raw=0x00000003 -> TERMINATES after 3 iterations (consumer range [0,255])
rxeof/poison   ring=2048 prod_raw=0x00008000 -> NEVER TERMINATES (equality unsatisfiable) after 16400 iterations (consumer range [0,2047])
rxeof/poison2  ring=2048 prod_raw=0x00001000 -> NEVER TERMINATES (equality unsatisfiable) after 16400 iterations (consumer range [0,2047])
txeof/poison   ring=512  prod_raw=0x00010000 -> NEVER TERMINATES (equality unsatisfiable) after 4112 iterations (consumer range [0,511])
events/poison  ring=256  prod_raw=0xffffffff -> NEVER TERMINATES (equality unsatisfiable) after 2064 iterations (consumer range [0,255])

Interrupt handler masks host interrupts before walking (if_ti.c:1778) and holds ifp->if_serializer: an unsatisfiable loop = hard CPU livelock.

RC_DF4068_MODEL=0
RC=0