Openmoko Bug #2232: unplugging with gadgetfs causes panic: "softlockup: blocked tasks"

[Openmoko Public Trac]

#2232: unplugging with gadgetfs causes panic: "softlockup: blocked tasks"
-----------------------------+----------------------------------------------
 Reporter:  lindi            |          Owner:  openmoko-kernel
     Type:  defect           |         Status:  in_testing     
 Priority:  normal           |      Milestone:                 
Component:  System Software  |        Version:  unspecified    
 Severity:  normal           |       Keywords:                 
 Haspatch:  0                |      Blockedby:                 
Estimated:                   |    Patchreview:                 
 Blocking:                   |   Reproducible:                 
-----------------------------+----------------------------------------------

Comment(by lindi):

 After a while I got another crash with same backtrace:
 {{{
 4007.055000] gta02_udc_command S3C2410_UDC_P_DISABLE
 4167.195000] INFO: task usb:3713 blocked for more than 120 seconds.
 4167.200000] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables
 this message.
 4167.205000] usb           D c03a6cbc     0  3713      1
 4167.215000] [<c03a6900>] (schedule+0x0/0x430) from [<bf01c504>]
 (ep_io+0x1fc/0x24c [gadgetfs])
 4167.220000] [<bf01c308>] (ep_io+0x0/0x24c [gadgetfs]) from [<bf01cf1c>]
 (ep_write+0x104/0x120 [gadgetfs])
 4167.230000] [<bf01ce18>] (ep_write+0x0/0x120 [gadgetfs]) from
 [<c00b21d4>] (vfs_write+0xb8/0x148)
 4167.245000]  r8:c0034048 r7:00001c00 r6:c6303f78 r5:40972200 r4:c4e416e0
 4167.250000] [<c00b211c>] (vfs_write+0x0/0x148) from [<c00b232c>]
 (sys_write+0x4c/0x7c)
 4167.255000]  r7:00000004 r6:c4e416e0 r5:00000000 r4:00000000
 4167.260000] [<c00b22e0>] (sys_write+0x0/0x7c) from [<c0033ea0>]
 (ret_fast_syscall+0x0/0x2c)
 4167.265000]  r6:4004b000 r5:40974490 r4:409744d8
 4167.270000] no locks held by usb/3713.
 4167.275000] Kernel panic - not syncing: softlockup: blocked tasks
 4167.280000] Rebooting in 10 seconds..<3>RCU detected CPU 0 stall
 (t=834039/600 jiffies)
 4170.195000] [<c03a6390>] (dump_stack+0x0/0x14) from [<c0085bd8>]
 (check_cpu_stall+0x80/0x100)
 4170.195000] [<c0085b58>] (check_cpu_stall+0x0/0x100) from [<c0085c70>]
 (__rcu_pending+0x18/0xa8)
 4170.195000]  r6:c782a080 r5:c04cb700 r4:c09a0924
 4170.195000] [<c0085c58>] (__rcu_pending+0x0/0xa8) from [<c0085d18>]
 (rcu_pending+0x18/0x4c)
 4170.195000]  r5:00000000 r4:00000000
 4170.195000] [<c0085d00>] (rcu_pending+0x0/0x4c) from [<c005f944>]
 (update_process_times+0x40/0x64)
 4170.195000] [<c005f904>] (update_process_times+0x0/0x64) from
 [<c0037e38>] (timer_tick+0x100/0x128)
 4170.195000]  r6:00000000 r5:00000000 r4:c04c8d48
 4170.195000] [<c0037d38>] (timer_tick+0x0/0x128) from [<c0044d90>]
 (s3c2410_timer_interrupt+0x10/0x18)
 4170.195000]  r4:c04c6524
 4170.195000] [<c0044d80>] (s3c2410_timer_interrupt+0x0/0x18) from
 [<c00830c8>] (handle_IRQ_event+0x2c/0x68)
 4170.195000] [<c008309c>] (handle_IRQ_event+0x0/0x68) from [<c00846d8>]
 (handle_edge_irq+0x12c/0x178)
 4170.195000]  r7:c04c9eac r6:c04c6524 r5:0000001e r4:c04c9e78
 4170.195000] [<c00845ac>] (handle_edge_irq+0x0/0x178) from [<c0033064>]
 (__exception_text_start+0x64/0x84)
 4170.195000]  r8:00000002 r7:00000003 r6:00004000 r5:00000000 r4:0000001e
 4170.195000] [<c0033000>] (__exception_text_start+0x0/0x84) from
 [<c0033a38>] (__irq_svc+0x38/0xc8)
 4170.195000] Exception stack(0xc782df10 to 0xc782df58)
 4170.195000] df00:                                     00017a8f 00000000
 000001e5 c04c9378
 4170.195000] df20: 00000000 00000ab5 c04f5040 000003e8 c04f5044 c04c936c
 c04c9378 c782df64
 4170.195000] df40: c782df58 c782df58 c03a6460 c01a4b0c 20000013 ffffffff
 4170.195000]  r5:f4000000 r4:ffffffff
 4170.195000] [<c03a63a4>] (panic+0x0/0x134) from [<c0082994>]
 (check_hung_uninterruptible_tasks+0x11c/0x17c)
 4170.195000]  r3:00000001 r2:c09a08fc r1:00000001 r0:c04562ec
 4170.195000] [<c0082878>] (check_hung_uninterruptible_tasks+0x0/0x17c)
 from [<c0082a9c>] (watchdog+0xa8/0xe4)
 4170.195000] [<c00829f4>] (watchdog+0x0/0xe4) from [<c006ae68>]
 (kthread+0x60/0x94)
 4170.195000] [<c006ae08>] (kthread+0x0/0x94) from [<c0058d80>]
 (do_exit+0x0/0x2a4)
 4170.195000]  r6:00000000 r5:00000000 r4:00000000
 }}}

-- 
Ticket URL: <https://docs.openmoko.org/trac/ticket/2232#comment:6>
docs.openmoko.org <http://docs.openmoko.org/trac/>
openmoko trac