Seen in my dmesg. Appears to have started in 2.6.33-rc7-mmotm0210, I can't remember if I reported it before or not... [ 0.212297] ACPI: Using IOAPIC for interrupt routing [ 0.340075] [ 0.340076] ============================================= [ 0.340241] [ INFO: possible recursive locking detected ] [ 0.340330] 2.6.33-mmotm0304 #5 [ 0.340415] --------------------------------------------- [ 0.340504] swapper/1 is trying to acquire lock: [ 0.340591] (&dev->mutex){+.+...}, at: [] __driver_attach+0x47/0x80 [ 0.340926] [ 0.340927] but task is already holding lock: [ 0.340999] (&dev->mutex){+.+...}, at: [] __driver_attach+0x39/0x80 [ 0.340999] [ 0.340999] other info that might help us debug this: [ 0.340999] 1 lock held by swapper/1: [ 0.340999] #0: (&dev->mutex){+.+...}, at: [] __driver_attach+0x39/0x80 [ 0.340999] [ 0.340999] stack backtrace: [ 0.340999] Pid: 1, comm: swapper Not tainted 2.6.33-mmotm0304 #5 [ 0.340999] Call Trace: [ 0.340999] [] __lock_acquire+0xc74/0xceb [ 0.340999] [] ? mark_lock+0x2d/0x22c [ 0.340999] [] ? __driver_attach+0x47/0x80 [ 0.340999] [] lock_acquire+0xf5/0x112 [ 0.340999] [] ? __driver_attach+0x47/0x80 [ 0.340999] [] ? mark_held_locks+0x52/0x70 [ 0.340999] [] __mutex_lock_common+0x5c/0x5aa [ 0.340999] [] ? __driver_attach+0x47/0x80 [ 0.340999] [] ? klist_next+0x24/0xd7 [ 0.340999] [] ? __driver_attach+0x47/0x80 [ 0.340999] [] ? __driver_attach+0x0/0x80 [ 0.340999] [] mutex_lock_nested+0x34/0x39 [ 0.340999] [] __driver_attach+0x47/0x80 [ 0.340999] [] ? __driver_attach+0x0/0x80 [ 0.340999] [] ? __driver_attach+0x0/0x80 [ 0.340999] [] bus_for_each_dev+0x54/0x89 [ 0.340999] [] driver_attach+0x19/0x1b [ 0.340999] [] bus_add_driver+0xb4/0x203 [ 0.340999] [] driver_register+0xb8/0x129 [ 0.340999] [] acpi_bus_register_driver+0x3e/0x40 [ 0.340999] [] acpi_ec_init+0x37/0x55 [ 0.340999] [] acpi_init+0x101/0x116 [ 0.340999] [] ? acpi_init+0x0/0x116 [ 0.340999] [] do_one_initcall+0x59/0x14e [ 0.340999] [] kernel_init+0x14d/0x1d7 [ 0.340999] [] kernel_thread_helper+0x4/0x10 [ 0.340999] [] ? restore_args+0x0/0x30 [ 0.340999] [] ? kernel_init+0x0/0x1d7 [ 0.340999] [] ? kernel_thread_helper+0x0/0x10 [ 0.341046] ACPI: EC: GPE = 0x11, I/O: command/status = 0x934, data = 0x930