The 'intel_idle_probe' probes the CPU and sets the CPU notifier. But if later on during the module initialization we fail (say in cpuidle_register_driver) we stop loading but we neglected to unregister the CPU notifier. This means that during CPU hotplug events the system will fail: calling intel_idle_init+0x0/0x326 @ 1 intel_idle: MWAIT substates: 0x1120 intel_idle: v0.4 model 0x2A intel_idle: lapic_timer_reliable_states 0xffffffff intel_idle: intel_idle yielding to none initcall intel_idle_init+0x0/0x326 returned -19 after 14 usecs ... some time later, offlining and onlining a CPU: cpu 3 spinlock event irq 62 BUG: unable to ] __cpuidle_register_device+0x1c/0x120 PGD 99b8b067 PUD 99b95067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: xen_evtchn nouveau mxm_wmi wmi radeon ttm i915 fbcon tileblit font atl1c bitblit softcursor drm_kms_helper video xen_blkfront xen_netfront fb_sys_fops sysimgblt sysfillrect syscopyarea xenfs xen_privcmd mperf CPU 0 Pid: 2302, comm: udevd Not tainted 3.8.0-rc3upstream-00249-g09ad159 #1 MSI MS-7680/H61M-P23 (MS-7680) RIP: e030:[<ffffffff814d956c>] [<ffffffff814d956c>] __cpuidle_register_device+0x1c/0x120 RSP: e02b:ffff88009dacfcb8 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff880105380000 RCX: 000000000000001c RDX: 0000000000000000 RSI: 0000000000000055 RDI: ffff880105380000 RBP: ffff88009dacfce8 R08: ffffffff81a4f048 R09: 0000000000000008 R10: 0000000000000008 R11: 0000000000000000 R12: ffff880105380000 R13: 00000000ffffffdd R14: 0000000000000000 R15: ffffffff81a523d0 FS: 00007f37bd83b7a0(0000) GS:ffff880105200000(0000) knlGS:0000000000000000 CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 00000000a09ea000 CR4: 0000000000042660 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process udevd (pid: 2302, threadinfo ffff88009dace000, task ffff88009afb47f0) Stack: ffffffff8107f2d0 ffffffff810c2fb7 ffff88009dacfce8 00000000ffffffea ffff880105380000 00000000ffffffdd ffff88009dacfd08 ffffffff814d9882 0000000000000003 ffff880105380000 ffff88009dacfd28 ffffffff81340afd Call Trace: [<ffffffff8107f2d0>] ? collect_cpu_info_local+0x30/0x30 [<ffffffff810c2fb7>] ? __might_sleep+0xe7/0x100 [<ffffffff814d9882>] cpuidle_register_device+0x32/0x70 [<ffffffff81340afd>] intel_idle_cpu_init+0xad/0x110 [<ffffffff81340bc8>] cpu_hotplug_notify+0x68/0x80 [<ffffffff8166023d>] notifier_call_chain+0x4d/0x70 [<ffffffff810bc369>] __raw_notifier_call_chain+0x9/0x10 [<ffffffff81094a4b>] __cpu_notify+0x1b/0x30 [<ffffffff81652cf7>] _cpu_up+0x103/0x14b [<ffffffff81652e18>] cpu_up+0xd9/0xec [<ffffffff8164a254>] store_online+0x94/0xd0 [<ffffffff814122fb>] dev_attr_store+0x1b/0x20 [<ffffffff81216404>] sysfs_write_file+0xf4/0x170 [<ffffffff811a1024>] vfs_write+0xb4/0x130 [<ffffffff811a17ea>] sys_write+0x5a/0xa0 [<ffffffff816643a9>] system_call_fastpath+0x16/0x1b Code: 03 18 00 c9 c3 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 48 83 ec 30 48 89 5d e8 4c 89 65 f0 48 89 fb 4c 89 6d f8 e8 84 08 00 00 <48> 8b 78 08 49 89 c4 e8 f8 7f c1 ff 89 c2 b8 ea ff ff ff 84 d2 RIP [<ffffffff814d956c>] __cpuidle_register_device+0x1c/0x120 RSP <ffff88009dacfcb8> This patch fixes it by moving the CPU notifier registration as the last item to be done by the module. Cc: stable@xxxxxxxxxxxxxxx # for 3.6 and above Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> Cc: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx> Cc: Rafael J. Wysocki <rjw@xxxxxxx> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> --- drivers/idle/intel_idle.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 4ba384f..2df9414 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -448,8 +448,6 @@ static int intel_idle_probe(void) else on_each_cpu(__setup_broadcast_timer, (void *)true, 1); - register_cpu_notifier(&cpu_hotplug_notifier); - pr_debug(PREFIX "v" INTEL_IDLE_VERSION " model 0x%X\n", boot_cpu_data.x86_model); @@ -612,6 +610,7 @@ static int __init intel_idle_init(void) return retval; } } + register_cpu_notifier(&cpu_hotplug_notifier); return 0; } -- 1.8.0.2 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
