On Thu, May 16, 2019 at 9:08 AM Andrew-sh.Cheng <andrew-sh.cheng@xxxxxxxxxxxx> wrote: > bool need_voltage_tracking; > + struct mutex lock; /* avoid notify and policy race condition */ > + struct notifier_block opp_nb; > + int opp_cpu; > + unsigned long opp_freq; > }; > > static LIST_HEAD(dvfs_info_list); > @@ -239,6 +243,7 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy, > vproc = dev_pm_opp_get_voltage(opp); > dev_pm_opp_put(opp); > > + mutex_lock(&info->lock); Should init mutex, otherwise it'll get lockdep warning: [ 0.587055] Call trace: [ 0.587069] dump_backtrace+0x0/0x168 [ 0.587077] show_stack+0x20/0x2c [ 0.587086] dump_stack+0xe4/0x134 [ 0.587095] register_lock_class+0x3e8/0x4b0 [ 0.587103] __lock_acquire+0xac/0x14e8 [ 0.587110] lock_acquire+0x1d0/0x208 [ 0.587118] __mutex_lock_common+0xc0/0xb40 [ 0.587126] mutex_lock_nested+0x40/0x50 [ 0.587135] mtk_cpufreq_set_target+0xcc/0x2a8 [ 0.587143] __cpufreq_driver_target+0x438/0x4d8 [ 0.587150] cpufreq_online+0x5b4/0x6e0 [ 0.587156] cpufreq_add_dev+0x4c/0x84 [ 0.587164] subsys_interface_register+0xb8/0x10c [ 0.587171] cpufreq_register_driver+0x11c/0x1c0 [ 0.587178] mtk_cpufreq_probe+0x378/0x4b8 [ 0.587185] platform_drv_probe+0x80/0xb0 [ 0.587192] really_probe+0x114/0x28c [ 0.587198] driver_probe_device+0x64/0xfc [ 0.587205] __device_attach_driver+0xb8/0xd0 [ 0.587211] bus_for_each_drv+0x88/0xd0 [ 0.587218] __device_attach+0xb0/0x134 [ 0.587224] device_initial_probe+0x20/0x2c [ 0.587230] bus_probe_device+0x34/0x94 [ 0.587238] device_add+0x520/0x5b4 [ 0.587245] platform_device_add+0x17c/0x208 [ 0.587252] platform_device_register_full+0xc0/0x100 [ 0.587261] mtk_cpufreq_driver_init+0x8c/0xdc [ 0.587268] do_one_initcall+0x1c0/0x3e0 [ 0.587276] do_initcall_level+0x1f4/0x224 [ 0.587282] do_basic_setup+0x34/0x4c [ 0.587288] kernel_init_freeable+0x10c/0x194 [ 0.587295] kernel_init+0x14/0x100 [ 0.587302] ret_from_fork+0x10/0x18 [ 0.587510] cpufreq: cpufreq_online: CPU4: Unlisted initial frequency changed to: 1248000 KHz
