请问有没有人遇到过下面这种情况：
gpio驱动模块加载正常，并且测试程序也正常，但是在卸载驱动的时候出现以下问题：
r7:c3ae5ec8 r6:c014d510 r5:c041a1c8 r4:00000253
[<c034edc8>] (dump_stack+0x0/0x1c) from [<c004af94>] (warn_slowpath_common+0x4c/
0x80)
[<c004af48>] (warn_slowpath_common+0x0/0x80) from [<c004b014>] (warn_slowpath_fm
t+0x30/0x38)
r7:c3ae4000 r6:bf0247d8 r5:00000880 r4:c3ae5eec
[<c004afe4>] (warn_slowpath_fmt+0x0/0x38) from [<c014d510>] (kobject_put+0x50/0x
64)
r3:00000000 r2:c041a1d8
r4:bf024914
[<c014d4c0>] (kobject_put+0x0/0x64) from [<c00a13e4>] (cdev_del+0x2c/0x34)
r4:bf024914
[<c00a13b8>] (cdev_del+0x0/0x34) from [<bf02457c>] (ARM_GPIO_CTL_release+0x2c/0x
44 [gpio_driver])
r5:00000880 r4:bf0248f8
[<bf024550>] (ARM_GPIO_CTL_release+0x0/0x44 [gpio_driver]) from [<c00711b8>] (sy
s_delete_module+0x18c/0x248)
r5:00000880 r4:00000000
[<c007102c>] (sys_delete_module+0x0/0x248) from [<c0031f20>] (ret_fast_syscall+0
x0/0x28)
r8:c00320c8 r7:00000081 r6:00000000 r5:00000001 r4:bec44f43
---[ end trace 0c73c3de7d9b91a9 ]---
rmmod: module 'gpio_driver' not found
是什么引起的呢？
