when cpsw is build as modulea and simple insert and removal of module
creates a deadlock, due to delete timer. the timer is created and destroyed
in cpsw_ale_start and cpsw_ale_stop which are from device open and close.
root@am437x-evm:~# modprobe -r ti_cpsw
[ 158.505333] INFO: trying to register non-static key.
[ 158.510623] the code is fine but needs lockdep annotation.
[ 158.516448] turning off the locking correctness validator.
[ 158.522282] CPU: 0 PID: 1339 Comm: modprobe Not tainted 3.14.23-00445-gd41c88f #44
[ 158.530359] [<c0015380>] (unwind_backtrace) from [<c0012088>] (show_stack+0x10/0x14)
[ 158.538603] [<c0012088>] (show_stack) from [<c054ad70>] (dump_stack+0x78/0x94)
[ 158.546295] [<c054ad70>] (dump_stack) from [<c0088008>] (__lock_acquire+0x176c/0x1b74)
[ 158.554711] [<c0088008>] (__lock_acquire) from [<c0088944>] (lock_acquire+0x9c/0x104)
[ 158.563043] [<c0088944>] (lock_acquire) from [<c004e520>] (del_timer_sync+0x44/0xd8)
[ 158.571289] [<c004e520>] (del_timer_sync) from [<bf2eac1c>] (cpsw_ale_destroy+0x10/0x3c [ti_cpsw])
[ 158.580821] [<bf2eac1c>] (cpsw_ale_destroy [ti_cpsw]) from [<bf2eb268>] (cpsw_remove+0x30/0xa0 [ti_cpsw])
[ 158.591000] [<bf2eb268>] (cpsw_remove [ti_cpsw]) from [<c035ef44>] (platform_drv_remove+0x18/0x1c)
[ 158.600527] [<c035ef44>] (platform_drv_remove) from [<c035d8bc>] (__device_release_driver+0x70/0xc8)
[ 158.610236] [<c035d8bc>] (__device_release_driver) from [<c035e0d4>] (driver_detach+0xb4/0xb8)
[ 158.619386] [<c035e0d4>] (driver_detach) from [<c035d6e4>] (bus_remove_driver+0x4c/0x90)
[ 158.627988] [<c035d6e4>] (bus_remove_driver) from [<c00af2a8>] (SyS_delete_module+0x10c/0x198)
[ 158.637144] [<c00af2a8>] (SyS_delete_module) from [<c000e580>] (ret_fast_syscall+0x0/0x48)
[ 179.524727] INFO: rcu_sched detected stalls on CPUs/tasks: {} (detected by 0, t=2102 jiffies, g=1487, c=1486, q=6)
[ 179.535741] INFO: Stall ended before state dump start
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
4484d0524e