cpufreq: Fix panic when setting sampling rate
Kernel panics when trying to set the sampling rate before the ondemand
governor CPUFREQ_GOV_START notification is received.
[<c078e500>] panic+0x15c
[<c0012354>] die+0x19c
[<c0018e60>] __do_kernel_fault+0x64
[<c0793660>] do_page_fault+0x3b8
[<c0008514>] do_DataAbort+0x134
[<c0791c58>] __dabt_svc+0x38
[<c02b5c68>] __list_add+0x38
[<c078f1b0>] __mutex_lock_slowpath+0x128
[<c078fc68>] mutex_lock+0x20
[<c05409c4>] store_sampling_rate+0x98
[<c02a6648>] kobj_attr_store+0x18
[<c0183124>] sysfs_write_file+0x108
[<c0131758>] vfs_write+0xac
[<c013188c>] sys_write+0x3c
[<c000e340>] ret_fast_syscall+0x0
Initialize the mutex as part of cpufreq_gov_dbs_init().
Change-Id: Ie9014407d724d7a0a81c076be47df5d08f513407
Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org>
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 5798c94..785ba6c 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -994,7 +994,6 @@
rc = input_register_handler(&dbs_input_handler);
mutex_unlock(&dbs_mutex);
- mutex_init(&this_dbs_info->timer_mutex);
if (!ondemand_powersave_bias_setspeed(
this_dbs_info->cur_policy,
@@ -1071,6 +1070,9 @@
return -EFAULT;
}
for_each_possible_cpu(i) {
+ struct cpu_dbs_info_s *this_dbs_info =
+ &per_cpu(od_cpu_dbs_info, i);
+ mutex_init(&this_dbs_info->timer_mutex);
INIT_WORK(&per_cpu(dbs_refresh_work, i), dbs_refresh_callback);
}