Hi Christopher,

Here speakup_con_update() tries to take the speakup_info.spinlock that
spk_var_store() already grabbed..

        [  311.320662] value for say_control out of range, expect 0 to 1
        [  311.321038] BUG: spinlock trylock failure on UP on CPU#0, trinity-child0/484
        [  311.321062]  lock: speakup_info, .magic: dead4ead, .owner: trinity-child0/484, .owner_cpu: 0
        [  311.321064] Pid: 484, comm: trinity-child0 Not tainted 3.5.0-rc5-01279-ga334b5f #44
        [  311.321065] Call Trace:
        [  311.321077]  [<ffffffff81364678>] spin_dump+0x9c/0xa1
        [  311.321079]  [<ffffffff813646ba>] spin_bug+0x3d/0x3f
        [  311.321082]  [<ffffffff813649d6>] do_raw_spin_trylock+0x82/0x8e
        [  311.321088]  [<ffffffff81b687f5>] _raw_spin_trylock+0x25/0x77
 ==>    [  311.321101]  [<ffffffff8184e5a3>] speakup_con_update+0xd4/0x1c8
        [  311.321103]  [<ffffffff8184edee>] vt_notifier_call+0x757/0x767
        [  311.321115]  [<ffffffff810835fe>] notifier_call_chain+0x32/0x8b
        [  311.321118]  [<ffffffff810837c6>] __atomic_notifier_call_chain+0x6f/0x9f
        [  311.321120]  [<ffffffff81083757>] ? atomic_notifier_chain_unregister+0x44/0x44
        [  311.321127]  [<ffffffff813a900d>] ? vgacon_set_cursor_size.isra.2+0x130/0x13d
        [  311.321130]  [<ffffffff81083805>] atomic_notifier_call_chain+0xf/0x11
        [  311.321140]  [<ffffffff814a0b0b>] notify_update+0x31/0x33
        [  311.321142]  [<ffffffff814a3162>] vt_console_print+0x490/0x4ab
        [  311.321150]  [<ffffffff81050f77>] call_console_drivers.constprop.7+0x181/0x19d
        [  311.321152]  [<ffffffff8105156e>] console_unlock+0x3b3/0x54a
        [  311.321154]  [<ffffffff81051d3d>] vprintk_emit+0x5ff/0x6c5
        [  311.321159]  [<ffffffff81b3fb65>] printk+0x48/0x4a
        [  311.321161]  [<ffffffff81851b93>] ? spk_var_store+0x83/0x3aa
 ==>    [  311.321163]  [<ffffffff81851c5d>] spk_var_store+0x14d/0x3aa
        [  311.321172]  [<ffffffff811e9ee6>] ? sysfs_get_active+0x149/0x157
        [  311.321175]  [<ffffffff811e86ad>] ? sysfs_write_file+0x15e/0x1dd
        [  311.321191]  [<ffffffff8133b705>] kobj_attr_store+0x28/0x34
        [  311.321194]  [<ffffffff811e86dd>] sysfs_write_file+0x18e/0x1dd
        [  311.321203]  [<ffffffff81165ba3>] vfs_write+0x155/0x247
        [  311.321206]  [<ffffffff81165d84>] sys_write+0x54/0x9b
        [  311.321210]  [<ffffffff81b6a037>] system_call_fastpath+0x16/0x1b

Thanks,
Fengguang