Android系统启动阶段多种快速重启系统方法试验记录

Android系统启动阶段多种快速重启系统方法试验记录

 

          笔者的系统是android4.2 A20平台，平台使用的是ext4文件系统。按我以前的经验对于nand来说yaffs对系统突然断电重启会好很多。笔者一个应用需求就是，系统启动到kernel，但是还没到应用能处理倒车事件的时候，笔者需要快速重启，让系统进入boot来完成倒车功能，这也是为了快速响应倒车影像。笔者使用了好几种重启系统的方法，都有一些问题，有的系统虽然能重启，但是因为文件系统由于突然掉电可能导致一些cash页没写成功，在boot阶段加载nand驱动的时候会去做repair，这个过程大概需要2秒多一点，对我们来说不大可靠。虽然笔者后续产品可能会使用inand来替代，但是还是把以前做过的一点事情分享给大家，大家有什么好的方法可以分享一下。有7种方法如下：

/*****************************************************************************************************/
声明：本博内容均由http://blog.csdn.net/edsam49原创，转载请注明出处，谢谢！
/*****************************************************************************************************/

一、使用emergency_restart(); 

二、handle_sysrq('u');//mountro

        handle_sysrq('b');//reboot

三、sys_sync();

        sys_restart_syscall();

四、sys_sync();

        kernel_restart(NULL);//LINUX_REBOOT_CMD_RESTART

五、sys_sync();

        sys_reboot(0xfee1dead, 0x28121969, 0x1234567,NULL);

六、sys_reboot(0xfee1dead,0x28121969, 0x1234567, NULL);

       加载内核过程中执行得话，系统crash；

 七、直接写watchdog的寄存器搞定，这样会使得在重启的时候boot阶段会做repair，会要耽误2秒钟左右，这也是比较难接受的。

 

下面是各种方法的相应打印信息，对应如下：

1、  使用emergency_restart();

/*

 * Emergency restart, callable from aninterrupt handler.

 */

 

[  208.862932] BUG: using smp_processor_id() inpreemptible [00000000] code: sh/2667

[  208.871614] caller is smp_send_stop+0x1c/0xe0

[  208.876582] [](unwind_backtrace+0x0/0xe0) from [](debug_smp_processor_id+0xbc/0xf0)

[  208.887427] [](debug_smp_processor_id+0xbc/0xf0) from [] (smp_send_stop+0x1c/0xe0)

[  208.898092] [](smp_send_stop+0x1c/0xe0) from [] (machine_restart+0xc/0x60)

[  208.907925] [](machine_restart+0xc/0x60) from [](reverseCar_proc_write+0x104/0x140)

[  208.918773] [] (reverseCar_proc_write+0x104/0x140)from [] (proc_file_write+0x78/0x94)

[  208.929731] [](proc_file_write+0x78/0x94) from [] (proc_reg_write+0x80/0x94)

[  208.939805] [](proc_reg_write+0x80/0x94) from [] (vfs_write+0xb0/0x128)

[  208.949372] [](vfs_write+0xb0/0x128) from [] (sys_write+0x3c/0x68)

[  208.958465] [](sys_write+0x3c/0x68) from [] (ret_fast_syscall+0x0/0x30)

[  208.968017] CPU0: stopping

[  208.971127] [] (unwind_backtrace+0x0/0xe0)from [] (handle_IPI+0xf8/0x1d4)

[  208.980867] [](handle_IPI+0xf8/0x1d4) from [] (gic_handle_irq+0x50/0x58)

[  208.990505] [](gic_handle_irq+0x50/0x58) from [] (__irq_svc+0x40/0x70)

[  208.999916] Exception stack(0xc06c5cf0 to0xc06c5d38)

[  209.005626] 5ce0:                                     0000040000000000 0fdcb000 c06c3140

[  209.014866] 5d00: df82d640 00000000 00000000df807a80 00000000 00000000 c06d4480 00000001

[  209.024100] 5d20: 00000000 c06c5d38 c0078ea8c00769c8 60000113 ffffffff

[  209.031592] [](__irq_svc+0x40/0x70) from [] (source_load+0x18/0x54)

[  209.040751] [](source_load+0x18/0x54) from [] (find_busiest_group+0x168/0x9c8)

[  209.050979] [](find_busiest_group+0x168/0x9c8) from [](load_balance+0xa0/0x630)

[  209.061396] [](load_balance+0xa0/0x630) from [](rebalance_domains+0xec/0x174)

[  209.071620] [](rebalance_domains+0xec/0x174) from [](run_rebalance_domains+0x30/0x128)

[  209.082726] [](run_rebalance_domains+0x30/0x128) from [](__do_softirq+0x94/0x12c)

[  209.093340] [](__do_softirq+0x94/0x12c) from [] (irq_exit+0x44/0x98)

[  209.102585] [](irq_exit+0x44/0x98) from [] (handle_IPI+0xac/0x1d4)

[  209.111639] [](handle_IPI+0xac/0x1d4) from [] (gic_handle_irq+0x50/0x58)

[  209.121277] [] (gic_handle_irq+0x50/0x58)from [] (__irq_svc+0x40/0x70)

[  209.130691] Exception stack(0xc06c5f68 to0xc06c5fb0)

[  209.136407] 5f60:                   00000003 01000000 0000000000000000 c06c4000 c070ba88

[  209.145647] 5f80: c04ad9b8 c06dbfd0 4000406a 410fc07400000000 00000000 00000000 c06c5fb0

[  209.154878] 5fa0: c000ea90 c000ea94 60000013ffffffff

[  209.160614] [](__irq_svc+0x40/0x70) from [] (default_idle+0x24/0x2c)

[  209.169866] [](default_idle+0x24/0x2c) from [] (cpu_idle+0x90/0xe4)

[  209.179025] [](cpu_idle+0x90/0xe4) from [] (start_kernel+0x2d8/0x334)

[  209.188350] [hotplug]: try to kill cpu:0failed!

[  209.193552]

[  209.195251] Restarting Linux version 3.4.39+(desheng@jeavox-server) (gcc version 4.6.3 20120201 (prerelease) (crosstool-NGlinaro-1.13.1-2012.02-20120222 - Linaro GCC 2012.02) ) #288 SMP PREEMPT Wed Dec11 11:39:14 HKT 2013

[  209.195302]

[  209.219501]sun7i_restart: to check

2、handle_sysrq('u');//mountro

        handle_sysrq('b');//reboot

[   66.797544] SysRq : Emergency Remount R/O

[   66.808076] SysRq : Resetting

[   66.811477] CPU0: stopping

[   66.814617] [](unwind_backtrace+0x0/0xe0) from [] (handle_IPI+0xf8/0x1d4)

[   66.824341] [](handle_IPI+0xf8/0x1d4) from [] (gic_handle_irq+0x50/0x58)

[   66.833966] [](gic_handle_irq+0x50/0x58) from [] (__irq_svc+0x40/0x70)

[   66.843365] Exception stack(0xd358be90 to0xd358bed8)

[   66.849058] be80:                                     df4e1b70 0000000000000000 df4e1c1c

[   66.858295] bea0: de986878 df4e1b70 df4c8620df4e1bb0 df4e1c40 dfa6cfc4 dfa6cfc0 00000000

[   66.867514] bec0: 00000000 d358bed8 c00e9c38c00e107c 20000013 ffffffff

[   66.875006] [](__irq_svc+0x40/0x70) from [] (__iget+0x8/0x1c)

[   66.883559] [](__iget+0x8/0x1c) from [] (sync_inodes_sb+0xfc/0x160)

[   66.892706] [](sync_inodes_sb+0xfc/0x160) from [](__sync_filesystem+0x50/0x94)

[   66.903042] [](__sync_filesystem+0x50/0x94) from [](do_remount_sb+0x54/0x144)

[   66.913251] [](do_remount_sb+0x54/0x144) from [](do_emergency_remount+0x88/0xf0)

[   66.923765] [](do_emergency_remount+0x88/0xf0) from [](process_one_work+0x1d0/0x31c)

[   66.934668] [](process_one_work+0x1d0/0x31c) from [](worker_thread+0x194/0x290)

[   66.945094] [](worker_thread+0x194/0x290) from [] (kthread+0x80/0x8c)

[   66.954422] [](kthread+0x80/0x8c) from [] (kernel_thread_exit+0x0/0x8)

[   66.963835] [hotplug]: try to kill cpu:0failed!

[   66.969061]

[   66.970759] Restarting Linux version 3.4.39+(desheng@jeavox-server) (gcc version 4.6.3 20120201 (prerelease) (crosstool-NGlinaro-1.13.1-2012.02-20120222 - Linaro GCC 2012.02) ) #284 SMP PREEMPT Tue Dec10 17:32:11 HKT 2013

[   66.970810]

[   66.994836] sun7i_restart: to check

 

3、 sys_sync();

        sys_restart_syscall();

重启不了

 

4、sys_sync();

        kernel_restart(NULL);//LINUX_REBOOT_CMD_RESTART

重启的时候太慢，有异常，卡了几秒钟，太慢了。

  126.005206]drivers/cpufreq/cpufreq.c:reboot_notifier_call: stop none boot cpus

[  126.016497] CPU1: shutdown

[  126.019916] [hotplug]: cpu(0) try to killcpu(1)

[  126.026327] [hotplug]: cpu1 is killed!

[  126.038924]drivers/cpufreq/cpufreq.c:reboot_notifier_call: stop none boot cpus done

[  126.168999] codec active: 0

[  126.172113] rest looping: 100

[  126.788816] sunxi_rtc_setaie(222): para 0

[  126.793314] WRN:L573(drivers/usb/host/ehci_sun7i.c):ERR:sw_ehci is disable, need not shutdown

[  126.802944] [sw-ohci1]: ohci shutdown start

[  126.807616] [sw-ohci1]: close clock

[  126.811521] [sw-ohci1]: ohci shutdown end

[  126.815988] [sw-ehci1]: ehci shutdown start

[  126.821212] [sw-ehci1]: Set USB Power OFF

[  126.825691] __set_vbus

[  126.828320] [sw-ehci1]: close clock

[  126.832266] [sw-ehci1]: ehci shutdown end

[  126.836801] wrn: hcd is disable, need notshutdown

[  126.842942] pmu_shutdown_chgcur = 1000000

[  126.848055] [NAND]shutdown

[  131.948829] nand try to shutdown 10 time

[  131.995235] Nand flash shutdown ok!

[  131.999177] devices shutdown time: 5948ms

[  132.003641] Disabling non-boot CPUs ...

[  132.007910] Restarting system.

[  132.011326]

[  132.012987] Restarting Linux version 3.4.39+(desheng@jeavox-server) (gcc version 4.6.3 20120201 (prerelease) (crosstool-NGlinaro-1.13.1-2012.02-20120222 - Linaro GCC 2012.02) ) #290 SMP PREEMPT Wed Dec11 17:03:17 HKT 2013

[  132.013004]

[  132.036965] sun7i_restart: to check

在启动过程中，IRQ中断handler里面执行得好，系统会crash。

    6.537818] WARNING: at kernel/softirq.c:159local_bh_enable_ip+0x4c/0xcc()

[    6.537827] Modules linked in: mali(O) lcddisp nand(O)

[    6.537874] [](unwind_backtrace+0x0/0xe0) from [](warn_slowpath_common+0x4c/0x64)

[    6.537898] [](warn_slowpath_common+0x4c/0x64) from [](warn_slowpath_null+0x18/0x1c)

[    6.537919] [](warn_slowpath_null+0x18/0x1c) from [] (local_bh_enable_ip+0x4c/0xcc)

[    6.537942] [](local_bh_enable_ip+0x4c/0xcc) from [](wakeup_flusher_threads+0x5c/0x84)

[    6.537965] [](wakeup_flusher_threads+0x5c/0x84) from [] (sys_sync+0x14/0x60)

[    6.537988] [] (sys_sync+0x14/0x60)from [] (syncfsAndReboot+0x8/0x14)

[    6.538014] [](syncfsAndReboot+0x8/0x14) from [](sw_reverseCar_irq_Handle+0x2c/0xb4)

[    6.538039] [](sw_reverseCar_irq_Handle+0x2c/0xb4) from [](gpio_irq_hdl+0x54/0x80)

[    6.538062] [](gpio_irq_hdl+0x54/0x80) from [](handle_irq_event_percpu+0x2c/0x16c)

[    6.538084] [](handle_irq_event_percpu+0x2c/0x16c) from [](handle_irq_event+0x3c/0x5c)

[    6.538105] [](handle_irq_event+0x3c/0x5c) from [](handle_fasteoi_irq+0xc8/0x114)

[    6.538127] [](handle_fasteoi_irq+0xc8/0x114) from [](generic_handle_irq+0x2c/0x40)

[    6.538150] [](generic_handle_irq+0x2c/0x40) from [] (handle_IRQ+0x78/0xb8)

[    6.538170] [](handle_IRQ+0x78/0xb8) from [] (gic_handle_irq+0x34/0x58)

[    6.538189] [](gic_handle_irq+0x34/0x58) from [] (__irq_svc+0x40/0x70)

[    6.538202] Exception stack(0xc06c5f68 to0xc06c5fb0)

[    6.538216] 5f60:                   00000003 01000000 0000000000000000 c06c4000 c070ba88

[    6.538233] 5f80: c04ad9b8 c06dbfd0 4000406a410fc074 00000000 00000000 00000000 c06c5fb0

[    6.538247] 5fa0: c000ea90 c000ea94 60000013ffffffff

[    6.538265] [](__irq_svc+0x40/0x70) from [] (default_idle+0x24/0x2c)

[    6.538285] [](default_idle+0x24/0x2c) from [] (cpu_idle+0x90/0xe4)

[    6.538312] [] (cpu_idle+0x90/0xe4)from [] (start_kernel+0x2d8/0x334)

[    6.538324] ---[ end trace 12bae582f8d57edc]---

[    6.538373] BUG: scheduling while atomic:swapper/0/0/0x00010002

[    6.538381] Modules linked in: mali(O) lcddisp nand(O)

[    6.538409] [](unwind_backtrace+0x0/0xe0) from [] (__schedule+0x70/0x4f0)

[    6.538431] [](__schedule+0x70/0x4f0) from [] (schedule_timeout+0x18/0x1c4)

[    6.538452] [](schedule_timeout+0x18/0x1c4) from [] (wait_for_common+0xc4/0x138)

[    6.538473] [](wait_for_common+0xc4/0x138) from [](writeback_inodes_sb_nr+0x8c/0x98)

[    6.538494] [](writeback_inodes_sb_nr+0x8c/0x98) from [](__sync_filesystem+0x5c/0x94)

[    6.538520] [](__sync_filesystem+0x5c/0x94) from [](iterate_supers+0x74/0xc8)

[    6.538542] [](iterate_supers+0x74/0xc8) from [] (sys_sync+0x28/0x60)

[    6.538561] [](sys_sync+0x28/0x60) from [] (syncfsAndReboot+0x8/0x14)

[    6.538582] [](syncfsAndReboot+0x8/0x14) from [](sw_reverseCar_irq_Handle+0x2c/0xb4)

[    6.538603] [](sw_reverseCar_irq_Handle+0x2c/0xb4) from [](gpio_irq_hdl+0x54/0x80)

[    6.538624] [](gpio_irq_hdl+0x54/0x80) from [](handle_irq_event_percpu+0x2c/0x16c)

[    6.538644] [](handle_irq_event_percpu+0x2c/0x16c) from [](handle_irq_event+0x3c/0x5c)

[    6.538665] [](handle_irq_event+0x3c/0x5c) from [](handle_fasteoi_irq+0xc8/0x114)

[    6.538685] [](handle_fasteoi_irq+0xc8/0x114) from [](generic_handle_irq+0x2c/0x40)

[    6.538705] [](generic_handle_irq+0x2c/0x40) from [] (handle_IRQ+0x78/0xb8)

[    6.538725] [](handle_IRQ+0x78/0xb8) from [] (gic_handle_irq+0x34/0x58)

[    6.538743] [](gic_handle_irq+0x34/0x58) from [] (__irq_svc+0x40/0x70

5、 sys_sync();

        sys_reboot(0xfee1dead, 0x28121969, 0x1234567,NULL);

 

[    3.874315] BUG: scheduling while atomic:swapper/0/0/0x00010002

[    3.881006] Modules linked in:

[    3.884451] [](unwind_backtrace+0x0/0xe0) from [] (__schedule+0x70/0x4f0)

[    3.894063] [] (__schedule+0x70/0x4f0)from [] (schedule_timeout+0x18/0x1c4)

[    3.903869] [](schedule_timeout+0x18/0x1c4) from [](wait_for_common+0xc4/0x138)

[    3.914149] [](wait_for_common+0xc4/0x138) from [] (kthread_create_on_node+0x68/0xd0)

[    3.924923] [](kthread_create_on_node+0x68/0xd0) from [](workqueue_cpu_callback.isra.21+0x48/0x20c)

[    3.937152] [](workqueue_cpu_callback.isra.21+0x48/0x20c) from [] (notifier_call_chain+0x38/0x68)

[    3.949082] [](notifier_call_chain+0x38/0x68) from [](__cpu_notify+0x28/0x40)

[    3.959178] [](__cpu_notify+0x28/0x40) from [] (_cpu_down+0x7c/0x21c)

[    3.968395] [] (_cpu_down+0x7c/0x21c)from [] (cpu_down+0x28/0x3c)

[    3.977234] [](cpu_down+0x28/0x3c) from [] (reboot_notifier_call+0x84/0xf4)

[    3.987022] [](reboot_notifier_call+0x84/0xf4) from [] (notifier_call_chain+0x38/0x68)

[    3.997877] [](notifier_call_chain+0x38/0x68) from [](__blocking_notifier_call_chain+0x44/0x58)

[    4.009705] [](__blocking_notifier_call_chain+0x44/0x58) from [](blocking_notifier_call_chain+0x14/0x18)

[    4.022407] [](blocking_notifier_call_chain+0x14/0x18) from [](kernel_restart_prepare+0x14/0x3c)

[    4.034335] [](kernel_restart_prepare+0x14/0x3c) from [](kernel_restart+0xc/0x4c)

[    4.044814] [](kernel_restart+0xc/0x4c) from [] (sys_reboot+0x184/0x1f0)

[    4.054329] [](sys_reboot+0x184/0x1f0) from [](sw_reverseCar_irq_Handle+0x2c/0xb4)

[    4.064906] [](sw_reverseCar_irq_Handle+0x2c/0xb4) from [](gpio_irq_hdl+0x54/0x80)

[    4.075481] [](gpio_irq_hdl+0x54/0x80) from [](handle_irq_event_percpu+0x2c/0x16c)

[    4.086059] [](handle_irq_event_percpu+0x2c/0x16c) from [](handle_irq_event+0x3c/0x5c)

[    4.097016] [](handle_irq_event+0x3c/0x5c) from [](handle_fasteoi_irq+0xc8/0x114)

[    4.107486] [](handle_fasteoi_irq+0xc8/0x114) from [](generic_handle_irq+0x2c/0x40)

[    4.118154] [] (generic_handle_irq+0x2c/0x40)from [] (handle_IRQ+0x78/0xb8)

[    4.127950] [](handle_IRQ+0x78/0xb8) from [] (gic_handle_irq+0x34/0x58)

[    4.137353] [](gic_handle_irq+0x34/0x58) from [] (__irq_svc+0x40/0x70)

[    4.146655] Exception stack(0xc06c5f68 to0xc06c5fb0)

[    4.152283] 5f60:                   00000003 01000000 0000000000000000 c06c4000 c070ba88

[    4.161400] 5f80: c04ad9b8 c06dbfd0 4000406a410fc074 00000000 00000000 00000000 c06c5fb0

[    4.170518] 5fa0: c000ea90 c000ea94 60000013ffffffff

[    4.176155] [](__irq_svc+0x40/0x70) from [] (default_idle+0x24/0x2c)

[    4.185267] [](default_idle+0x24/0x2c) from [] (cpu_idle+0x90/0xe4)

[    4.194295] [] (cpu_idle+0x90/0xe4)from [] (start_kernel+0x2d8/0x334)

[    4.203514] [](start_kernel+0x2d8/0x334) from [<40008044>] (0x40008044)

[    4.211947] bad: scheduling from the idlethread!

[    4.217192] [](unwind_backtrace+0x0/0xe0) from [](dequeue_task_idle+0x18/0x28)

[    4.227381] [](dequeue_task_idle+0x18/0x28) from [] (dequeue_task+0x30/0x34)

[    4.237272] [](dequeue_task+0x30/0x34) from [] (__schedule+0xd4/0x4f0)

[    4.246589] [](__schedule+0xd4/0x4f0) from [] (schedule_timeout+0x18/0x1c4)

[    4.256390] [](schedule_timeout+0x18/0x1c4) from [](wait_for_common+0xc4/0x138)

[    4.266676] [](wait_for_common+0xc4/0x138) from [](kthread_create_on_node+0x68/0xd0)

[    4.277444] [](kthread_create_on_node+0x68/0xd0) from [](workqueue_cpu_callback.isra.21+0x48/0x20c)

[    4.289662] [](workqueue_cpu_callback.isra.21+0x48/0x20c) from [](notifier_call_chain+0x38/0x68)

[    4.301587] [](notifier_call_chain+0x38/0x68) from [](__cpu_notify+0x28/0x40)

[    4.311680] [](__cpu_notify+0x28/0x40) from [] (_cpu_down+0x7c/0x21c)

[    4.320901] [](_cpu_down+0x7c/0x21c) from [] (cpu_down+0x28/0x3c)

[    4.329726] [](cpu_down+0x28/0x3c) from [] (reboot_notifier_call+0x84/0xf4)

[    4.339522] [](reboot_notifier_call+0x84/0xf4) from [] (notifier_call_chain+0x38/0x68)

[    4.350392] [](notifier_call_chain+0x38/0x68) from [](__blocking_notifier_call_chain+0x44/0x58)

[    4.362228] [](__blocking_notifier_call_chain+0x44/0x58) from [](blocking_notifier_call_chain+0x14/0x18)

[    4.374932] [](blocking_notifier_call_chain+0x14/0x18) from [](kernel_restart_prepare+0x14/0x3c)

[    4.386869] [](kernel_restart_prepare+0x14/0x3c) from [](kernel_restart+0xc/0x4c)

[    4.397347] [](kernel_restart+0xc/0x4c) from [] (sys_reboot+0x184/0x1f0)

6、 sys_reboot(0xfee1dead, 0x28121969, 0x1234567,NULL);

加载内核过程中执行得话，系统crash；

   70.309402] SYSCALL_DEFINE4: rebootmagic1=0xfee1dead, magic2=0x28121969, cmd=0x1234567

[   70.318745]drivers/cpufreq/cpufreq.c:reboot_notifier_call: stop none boot cpus

[   70.339919] CPU1: shutdown

[   70.343016] [hotplug]: cpu(0) try to killcpu(1)

[   70.349214] [hotplug]: cpu1 is killed!

[   70.353905]drivers/cpufreq/cpufreq.c:reboot_notifier_call: stop none boot cpus done

[   70.479995] codec active: 0

[   70.483109] rest looping: 100

[   71.100040] sunxi_rtc_setaie(222): para 0

[   71.104541] WRN:L573(drivers/usb/host/ehci_sun7i.c):ERR:sw_ehci is disable, need not shutdown

[   71.114179] [sw-ohci1]: ohci shutdown start

[   71.118851] [sw-ohci1]: close clock

[   71.122756] [sw-ohci1]: ohci shutdown end

[   71.127226] [sw-ehci1]: ehci shutdown start

[   71.132254] [sw-ehci1]: Set USB Power OFF

[   71.136716] __set_vbus

[   71.139340] [sw-ehci1]: close clock

[   71.143240] [sw-ehci1]: ehci shutdown end

[   71.147775] wrn: hcd is disable, need notshutdown

[   71.153941] pmu_shutdown_chgcur = 1000000

[   71.159055] [NAND]shutdown

[   76.259791] nand try to shutdown 10 time

[   76.302211] Nand flash shutdown ok!

[   76.306122] devices shutdown time: 5937ms

[   76.310613] Disabling non-boot CPUs ...

[   76.315034] Restarting system.

[   76.318435]

[   76.320121] Restarting Linux version 3.4.39+(desheng@jeavox-server) (gcc version 4.6.3 20120201 (prerelease) (crosstool-NGlinaro-1.13.1-2012.02-20120222 - Linaro GCC 2012.02) ) #292 SMP PREEMPT Wed Dec11 17:38:15 HKT 2013

[   76.320138]

[   76.343958] sun7i_restart: to check

 

    8.891894] WARNING: at fs/sysfs/dir.c:508sysfs_add_one+0x78/0x98()

[    8.899237] sysfs: cannot create duplicatefilename '/class/custom_design'

[    8.907153] Modules linked in:custom_design_drv(+) sunxi_csi0 ov7725 camera videobuf_dma_contig videobuf_coresecurity_system ektf2k mali(O) lcd disp nand(O)

[    8.923458] [](unwind_backtrace+0x0/0xe0) from [](warn_slowpath_common+0x4c/0x64)

[    8.934210] [](warn_slowpath_common+0x4c/0x64) from [](warn_slowpath_fmt+0x2c/0x3c)

[    8.950510] [](warn_slowpath_fmt+0x2c/0x3c) from [] (sysfs_add_one+0x78/0x98)

[    8.960708] [](sysfs_add_one+0x78/0x98) from [] (create_dir+0x5c/0xac)

[    8.974839] [](create_dir+0x5c/0xac) from [] (sysfs_create_dir+0xb8/0xd8)

[    8.984705] [](sysfs_create_dir+0xb8/0xd8) from [](kobject_add_internal+0xc4/0x1c8)

[    8.998438] [](kobject_add_internal+0xc4/0x1c8) from [](kset_register+0x20/0x3c)

[    9.010851] [](kset_register+0x20/0x3c) from [] (__class_register+0xac/0x198)

[    9.021160] [](__class_register+0xac/0x198) from [](__class_create+0x40/0x6c)

[    9.031540] [](__class_create+0x40/0x6c) from [](custom_design_init+0x98/0x40c [custom_design_drv])

[    9.044078] [](custom_design_init+0x98/0x40c [custom_design_drv]) from [](do_one_initcall+0x90/0x160)

[    9.056658] [](do_one_initcall+0x90/0x160) from [](sys_init_module+0x1704/0x18f0)

[    9.067287] [](sys_init_module+0x1704/0x18f0) from [](ret_fast_syscall+0x0/0x30)

[    9.082747] ---[ end trace a90fd0205139c366]---

[    9.087932] ------------[ cut here]------------

[    9.098729] WARNING: at lib/kobject.c:198kobject_add_internal+0x150/0x1c8()

[    9.106623] kobject_add_internal failed forcustom_design with -EEXIST, don't try to register things with the same name inthe same directory.

[    9.132884] Modules linked in:custom_design_drv(+) sunxi_csi0 ov7725 camera videobuf_dma_contig videobuf_coresecurity_system

[    9.145147] ###########close all layers 0,hdl 103

[    9.151230] ektf2k mali(O) lcd disp nand(O)

[    9.161724] [](unwind_backtrace+0x0/0xe0) from [](warn_slowpath_common+0x4c/0x64)

[    9.172531] [](warn_slowpath_common+0x4c/0x64) from [](warn_slowpath_fmt+0x2c/0x3c)

[    9.183407] [](warn_slowpath_fmt+0x2c/0x3c) from [](kobject_add_internal+0x150/0x1c8)

[    9.194411] [](kobject_add_internal+0x150/0x1c8) from [](kset_register+0x20/0x3c)

[    9.205060] [](kset_register+0x20/0x3c) from [] (__class_register+0xac/0x198)

[    9.215317] [](__class_register+0xac/0x198) from [](__class_create+0x40/0x6c)

[    9.225671] [](__class_create+0x40/0x6c) from [](custom_design_init+0x98/0x40c [custom_design_drv])

[    9.238418] [](custom_design_init+0x98/0x40c [custom_design_drv]) from [](do_one_initcall+0x90/0x160)

[    9.255590] [](do_one_initcall+0x90/0x160) from [](sys_init_module+0x1704/0x18f0)

[    9.270886] [] (sys_init_module+0x1704/0x18f0)from [] (ret_fast_syscall+0x0/0x30)

[    9.286004] ---[ end trace a90fd0205139c367]---

[    9.291276] class_create() failed 0

[    9.295263] init: command 'insmod' r=0

[    9.304720] init: starting 'reversemonitor'

[    9.352176] [TVD_INF]V4L2 device registeredas video1

[    9.358686] init: command 'insmod' r=0

[    9.386257] init: command 'insmod' r=0

[    9.428488] usbcore: registered new interfacedriver asix

[    9.434609] init: command 'insmod' r=0

[    9.463388] usbcore: registered new interfacedriver qf9700

[    9.469848] init: command 'insmod' r=0

[    9.497221] usbcore: registered new interfacedriver MOSCHIP usb-ethernet driver

[    9.505800] init: command 'insmod' r=0

[    9.529954] usbcore: registered new interfacedriver cdc_ether

[    9.536568] init: command 'insmod' r=0

[    9.545432] init: processing action 0x381d0(queue_property_triggers)

[    9.552936] init: command'queue_property_triggers' r=0

[    9.559380] init: processing action 0x30678 (property:ro.debuggable=1)

[    9.566925] init: starting 'console'

[    9.571673] init: command 'start' r=0

 

7、直接写watchdog的寄存器搞定，这样会使得在重启的时候boot阶段会做repair，会要耽误2秒钟左右，这也是比较难接受的。