[  138.940095] 
[  138.941685] =============================================
[  138.947320] [ INFO: possible recursive locking detected ]
[  138.952956] 4.6.0 #66 Tainted: G        W      
[  138.957678] ---------------------------------------------
[  138.963307] interpreter/380 is trying to acquire lock:
[  138.968662]  (&port_lock_key){-.-...}, at: [<c04bb29c>] uart_write_room+0x10/0x3c
[  138.976525] 
[  138.976525] but task is already holding lock:
[  138.982611]  (&port_lock_key){-.-...}, at: [<c04c7538>] serial_omap_irq+0x14/0x3c4
[  138.990546] 
[  138.990546] other info that might help us debug this:
[  138.997354]  Possible unsafe locking scenario:
[  138.997354] 
[  139.003526]        CPU0
[  139.006075]        ----
[  139.008623]   lock(&port_lock_key);
[  139.012267]   lock(&port_lock_key);
[  139.015919] 
[  139.015919]  *** DEADLOCK ***
[  139.015919] 
[  139.022092]  May be due to missing lock nesting notation
[  139.022092] 
[  139.029179] 2 locks held by interpreter/380:
[  139.033627]  #0:  (&port_lock_key){-.-...}, at: [<c04c7538>] serial_omap_irq+0x14/0x3c4
[  139.042010]  #1:  (&tty->ldisc_sem){++++++}, at: [<c04a855c>] tty_ldisc_ref+0x14/0x48
[  139.050213] 
[  139.050213] stack backtrace:
[  139.054765] CPU: 0 PID: 380 Comm: interpreter Tainted: G        W       4.6.0 #66
[  139.062565] Hardware name: Generic AM33XX (Flattened Device Tree)
[  139.068953] [<c010d4e0>] (unwind_backtrace) from [<c010b968>] (show_stack+0x10/0x14)
[  139.077051] [<c010b968>] (show_stack) from [<c0167398>] (__lock_acquire+0x920/0x1ce8)
[  139.085227] [<c0167398>] (__lock_acquire) from [<c016901c>] (lock_acquire+0xa8/0x12c)
[  139.093406] [<c016901c>] (lock_acquire) from [<c081e0c4>] (_raw_spin_lock_irqsave+0x38/0x4c)
[  139.102213] [<c081e0c4>] (_raw_spin_lock_irqsave) from [<c04bb29c>] (uart_write_room+0x10/0x3c)
[  139.111329] [<c04bb29c>] (uart_write_room) from [<bf05b324>] (gsmld_output+0x18/0x98 [n_gsm])
[  139.120251] [<bf05b324>] (gsmld_output [n_gsm]) from [<bf05a2a4>] (gsm_data_kick+0x88/0x168 [n_gsm])
[  139.129802] [<bf05a2a4>] (gsm_data_kick [n_gsm]) from [<bf05b6e4>] (gsmld_write_wakeup+0x28/0x5c [n_gsm])
[  139.139820] [<bf05b6e4>] (gsmld_write_wakeup [n_gsm]) from [<c049eb34>] (tty_wakeup+0x50/0x5c)
[  139.148812] [<c049eb34>] (tty_wakeup) from [<c04c7840>] (serial_omap_irq+0x31c/0x3c4)
[  139.157007] [<c04c7840>] (serial_omap_irq) from [<c017a470>] (handle_irq_event_percpu+0x54/0x204)
[  139.166270] [<c017a470>] (handle_irq_event_percpu) from [<c017a658>] (handle_irq_event+0x38/0x5c)
[  139.175534] [<c017a658>] (handle_irq_event) from [<c017cfc8>] (handle_level_irq+0xa0/0x130)
[  139.184256] [<c017cfc8>] (handle_level_irq) from [<c0179c50>] (generic_handle_irq+0x20/0x34)
[  139.193059] [<c0179c50>] (generic_handle_irq) from [<c0179ed8>] (__handle_domain_irq+0x48/0xa8)
[  139.202138] [<c0179ed8>] (__handle_domain_irq) from [<c081e8f8>] (__irq_svc+0x58/0x78)
[  139.210407] [<c081e8f8>] (__irq_svc) from [<c081e234>] (_raw_spin_unlock_irq+0x28/0x2c)
[  139.218771] [<c081e234>] (_raw_spin_unlock_irq) from [<c014ef70>] (finish_task_switch+0xb8/0x23c)
[  139.228030] [<c014ef70>] (finish_task_switch) from [<c081a270>] (schedule+0x48/0xa0)
[  139.236110] [<c081a270>] (schedule) from [<c081db84>] (do_nanosleep+0x84/0x140)
[  139.243748] [<c081db84>] (do_nanosleep) from [<c0186ca8>] (hrtimer_nanosleep+0xa0/0x12c)
[  139.252200] [<c0186ca8>] (hrtimer_nanosleep) from [<c0186dc8>] (SyS_nanosleep+0x94/0xcc)
[  139.260649] [<c0186dc8>] (SyS_nanosleep) from [<c0107540>] (ret_fast_syscall+0x0/0x1c)
[  145.245792] BUG: spinlock lockup suspected on CPU#0, interpreter/380
[  145.252426]  lock: 0xce353418, .magic: dead4ead, .owner: interpreter/380, .owner_cpu: 0
[  145.260783] CPU: 0 PID: 380 Comm: interpreter Tainted: G        W       4.6.0 #66
[  145.268590] Hardware name: Generic AM33XX (Flattened Device Tree)
[  145.274962] [<c010d4e0>] (unwind_backtrace) from [<c010b968>] (show_stack+0x10/0x14)
[  145.283057] [<c010b968>] (show_stack) from [<c016bd38>] (do_raw_spin_lock+0x144/0x16c)
[  145.291328] [<c016bd38>] (do_raw_spin_lock) from [<c081e0cc>] (_raw_spin_lock_irqsave+0x40/0x4c)
[  145.300500] [<c081e0cc>] (_raw_spin_lock_irqsave) from [<c04bb29c>] (uart_write_room+0x10/0x3c)
[  145.309594] [<c04bb29c>] (uart_write_room) from [<bf05b324>] (gsmld_output+0x18/0x98 [n_gsm])
[  145.318518] [<bf05b324>] (gsmld_output [n_gsm]) from [<bf05a2a4>] (gsm_data_kick+0x88/0x168 [n_gsm])
[  145.328073] [<bf05a2a4>] (gsm_data_kick [n_gsm]) from [<bf05b6e4>] (gsmld_write_wakeup+0x28/0x5c [n_gsm])
[  145.338070] [<bf05b6e4>] (gsmld_write_wakeup [n_gsm]) from [<c049eb34>] (tty_wakeup+0x50/0x5c)
[  145.347065] [<c049eb34>] (tty_wakeup) from [<c04c7840>] (serial_omap_irq+0x31c/0x3c4)
[  145.355242] [<c04c7840>] (serial_omap_irq) from [<c017a470>] (handle_irq_event_percpu+0x54/0x204)
[  145.364499] [<c017a470>] (handle_irq_event_percpu) from [<c017a658>] (handle_irq_event+0x38/0x5c)
[  145.373762] [<c017a658>] (handle_irq_event) from [<c017cfc8>] (handle_level_irq+0xa0/0x130)
[  145.382482] [<c017cfc8>] (handle_level_irq) from [<c0179c50>] (generic_handle_irq+0x20/0x34)
[  145.391290] [<c0179c50>] (generic_handle_irq) from [<c0179ed8>] (__handle_domain_irq+0x48/0xa8)
[  145.400381] [<c0179ed8>] (__handle_domain_irq) from [<c081e8f8>] (__irq_svc+0x58/0x78)
[  145.408648] [<c081e8f8>] (__irq_svc) from [<c081e234>] (_raw_spin_unlock_irq+0x28/0x2c)
[  145.417003] [<c081e234>] (_raw_spin_unlock_irq) from [<c014ef70>] (finish_task_switch+0xb8/0x23c)
[  145.426265] [<c014ef70>] (finish_task_switch) from [<c081a270>] (schedule+0x48/0xa0)
[  145.434343] [<c081a270>] (schedule) from [<c081db84>] (do_nanosleep+0x84/0x140)
[  145.441973] [<c081db84>] (do_nanosleep) from [<c0186ca8>] (hrtimer_nanosleep+0xa0/0x12c)
[  145.450417] [<c0186ca8>] (hrtimer_nanosleep) from [<c0186dc8>] (SyS_nanosleep+0x94/0xcc)
[  145.458865] [<c0186dc8>] (SyS_nanosleep) from [<c0107540>] (ret_fast_syscall+0x0/0x1c)
[  152.423669] BUG: spinlock lockup suspected on CPU#0, swapper/0
[  152.429789]  lock: 0xce353418, .magic: dead4ead, .owner: swapper/0, .owner_cpu: 0
[  152.437602] CPU: 0 PID: 0 Comm: swapper Tainted: G        W       4.6.0 #66
[  152.444864] Hardware name: Generic AM33XX (Flattened Device Tree)
[  152.451258] [<c010d4e0>] (unwind_backtrace) from [<c010b968>] (show_stack+0x10/0x14)
[  152.459356] [<c010b968>] (show_stack) from [<c016bd38>] (do_raw_spin_lock+0x144/0x16c)
[  152.467626] [<c016bd38>] (do_raw_spin_lock) from [<c081e0cc>] (_raw_spin_lock_irqsave+0x40/0x4c)
[  152.476812] [<c081e0cc>] (_raw_spin_lock_irqsave) from [<c04bb29c>] (uart_write_room+0x10/0x3c)
[  152.485925] [<c04bb29c>] (uart_write_room) from [<bf05b324>] (gsmld_output+0x18/0x98 [n_gsm])
[  152.494842] [<bf05b324>] (gsmld_output [n_gsm]) from [<bf05a2a4>] (gsm_data_kick+0x88/0x168 [n_gsm])
[  152.504391] [<bf05a2a4>] (gsm_data_kick [n_gsm]) from [<bf05b6e4>] (gsmld_write_wakeup+0x28/0x5c [n_gsm])
[  152.514402] [<bf05b6e4>] (gsmld_write_wakeup [n_gsm]) from [<c049eb34>] (tty_wakeup+0x50/0x5c)
[  152.523409] [<c049eb34>] (tty_wakeup) from [<c04c7840>] (serial_omap_irq+0x31c/0x3c4)
[  152.531596] [<c04c7840>] (serial_omap_irq) from [<c017a470>] (handle_irq_event_percpu+0x54/0x204)
[  152.540857] [<c017a470>] (handle_irq_event_percpu) from [<c017a658>] (handle_irq_event+0x38/0x5c)
[  152.550119] [<c017a658>] (handle_irq_event) from [<c017cfc8>] (handle_level_irq+0xa0/0x130)
[  152.558836] [<c017cfc8>] (handle_level_irq) from [<c0179c50>] (generic_handle_irq+0x20/0x34)
[  152.567642] [<c0179c50>] (generic_handle_irq) from [<c0179ed8>] (__handle_domain_irq+0x48/0xa8)
[  152.576722] [<c0179ed8>] (__handle_domain_irq) from [<c081e8f8>] (__irq_svc+0x58/0x78)
[  152.584989] [<c081e8f8>] (__irq_svc) from [<c0107e4c>] (arch_cpu_idle+0x20/0x3c)
[  152.592710] [<c0107e4c>] (arch_cpu_idle) from [<c015d04c>] (cpu_startup_entry+0x1b0/0x220)
[  152.601341] [<c015d04c>] (cpu_startup_entry) from [<c0c00c14>] (start_kernel+0x334/0x3ac)