# Rig: ssdt_b2.aml (valid-length 0x78-port regions; AAA0@0x4cc, AAA2@0x8e)
#
# BASELINE (unmodified /boot/kernel/apple_gmux.ko) -- same state machine, then:
gmuxtrig: vga_switcheroo handler_flags = 0x1 (CAN_SWITCH_DDC=1)
gmuxtrig: calling vga_switcheroo_force_migd() -> gmux_switchto on clobbered apple_gmux_softc_data...
Fatal trap 12: page fault while in kernel mode
fault virtual address = 0x60
fault code = supervisor write data, page not present
Stopped at      gmux_switchto+0x10:     movl    %edi,0x60(%rbx)
# (full capture in panic.b2.txt; guest wedged in DDB)
#
# PATCHED STEP 1 (guards + conditional clear only):
gmuxtrig: force_migd returned -19, NO PANIC
# crash gone; global still clobbered (line 867 unconditional set), handler dead
#
# PATCHED STEP 2 (complete fix.diff incl. global-ownership hunk):
apple_gmux: Failed to register vga_switcheroo handler
device_probe_and_attach: apple_gmux1 attach returned -22
gmuxtrig: vga_switcheroo handler_flags = 0x1 (CAN_SWITCH_DDC=1)
gmuxtrig: force_migd returned 0, NO PANIC
 2:35AM   up 18 secs, 0 users, load averages: 0.21, 0.05, 0.02
# no panic; surviving instance keeps serving dispatches (return 0)