Comment 1 for bug 1711401

Device is OK with 4.12, however, with 4.12 we get another issue:

[ 3996.652718] INFO: rcu_sched self-detected stall on CPU
[ 3996.652730] 23-...: (1 GPs behind) idle=73a/140000000000002/0 softirq=5179/5179 fqs=2475
[ 3996.652735] (t=5250 jiffies g=6889 c=6888 q=189)
[ 3996.652748] Task dump for CPU 23:
[ 3996.652749] kopald S 0 975 2 0x00000804
[ 3996.652752] Call Trace:
[ 3996.652759] [c000000fefafb0b0] [c000000000135a24] sched_show_task+0xd4/0x150 (unreliable)
[ 3996.652763] [c000000fefafb120] [c000000000c36b3c] rcu_dump_cpu_stacks+0xd0/0x134
[ 3996.652767] [c000000fefafb170] [c0000000001867a0] rcu_check_callbacks+0x8a0/0xb10
[ 3996.652769] [c000000fefafb2a0] [c000000000192958] update_process_times+0x48/0x90
[ 3996.652773] [c000000fefafb2d0] [c0000000001a9f60] tick_sched_handle.isra.8+0x30/0xb0
[ 3996.652775] [c000000fefafb300] [c0000000001aa044] tick_sched_timer+0x64/0xd0
[ 3996.652778] [c000000fefafb340] [c000000000193424] __hrtimer_run_queues+0x144/0x370
[ 3996.652780] [c000000fefafb3c0] [c00000000019449c] hrtimer_interrupt+0xfc/0x350
[ 3996.652784] [c000000fefafb490] [c000000000024658] __timer_interrupt+0x88/0x250
[ 3996.652787] [c000000fefafb4e0] [c000000000024a30] timer_interrupt+0x90/0xe0
[ 3996.652791] [c000000fefafb510] [c00000000000b6e0] restore_check_irq_replay+0x54/0x70
[ 3996.652795] --- interrupt: 901 at arch_local_irq_restore+0x74/0x90
                   LR = arch_local_irq_restore+0x74/0x90
[ 3996.652797] [c000000fefafb800] [c000000000194530] hrtimer_interrupt+0x190/0x350 (unreliable)
[ 3996.652801] [c000000fefafb820] [c000000000c3298c] __do_softirq+0xcc/0x41c
[ 3996.652804] [c000000fefafb900] [c0000000000fafa8] irq_exit+0xe8/0x120
[ 3996.652807] [c000000fefafb920] [c000000000024a34] timer_interrupt+0x94/0xe0
[ 3996.652810] [c000000fefafb950] [c00000000000b6e0] restore_check_irq_replay+0x54/0x70
[ 3996.652815] --- interrupt: 901 at lock_timer_base+0x70/0x100
                   LR = schedule_timeout+0x334/0x420
[ 3996.652817] [c000000fefafbc40] [0000000000000001] 0x1 (unreliable)
[ 3996.652821] [c000000fefafbca0] [c000000000c30a14] schedule_timeout+0x334/0x420
[ 3996.652824] [c000000fefafbd80] [c000000000095bf0] kopald+0x90/0xe0
[ 3996.652827] [c000000fefafbdc0] [c0000000001214cc] kthread+0x1ac/0x1c0
[ 3996.652831] [c000000fefafbe30] [c00000000000b2e8] ret_from_kernel_thread+0x5c/0x74
[ 4000.060643] NMI watchdog: BUG: soft lockup - CPU#23 stuck for 23s! [kopald:975]
[ 4000.060653] Modules linked in: kvm_hv kvm_pr kvm cuse userio hci_vhci bluetooth ecdh_generic uhid hid vhost_net vhost tap snd_seq snd_seq_device snd_timer snd soundcore powernv_op_panel uio_pdrv_genirq ipmi_powernv ipmi_devintf powernv_rng leds_powernv ibmpowernv vmx_crypto ipmi_msghandler uio ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear dm_round_robin ses enclosure scsi_transport_sas crct10dif_vpmsum crc32c_vpmsum tg3 ipr scsi_dh_emc scsi_dh_rdac scsi_dh_alua dm_multipath
[ 4000.060735] CPU: 23 PID: 975 Comm: kopald Not tainted 4.12.0-11-generic #12
[ 4000.060737] task: c000000fefa5b800 task.stack: c000000fefaf8000
[ 4000.060739] NIP: c0000000000165f4 LR: c0000000000165f4 CTR: c000000000024200
[ 4000.060740] REGS: c000000fefafb580 TRAP: 0901 Not tainted (4.12.0-11-generic)
[ 4000.060741] MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE>
[ 4000.060748] CR: 28000224 XER: 20000000
[ 4000.060749] CFAR: c000000000024a30 SOFTE: 1
               GPR00: c000000000c3298c c000000fefafb800 c0000000015a8e00 0000000000000900
               GPR04: c000000fffac0400 0000000000000000 0000000001f4024e c000000fefa5b800
               GPR08: 0000000000000000 c000000fefaf8000 0000000000000000 0000000000000005
               GPR12: c0000000000920b8 c00000000facf180
[ 4000.060764] NIP [c0000000000165f4] arch_local_irq_restore+0x74/0x90
[ 4000.060766] LR [c0000000000165f4] arch_local_irq_restore+0x74/0x90
[ 4000.060767] Call Trace:
[ 4000.060769] [c000000fefafb800] [c000000000194530] hrtimer_interrupt+0x190/0x350 (unreliable)
[ 4000.060773] [c000000fefafb820] [c000000000c3298c] __do_softirq+0xcc/0x41c
[ 4000.060776] [c000000fefafb900] [c0000000000fafa8] irq_exit+0xe8/0x120
[ 4000.060779] [c000000fefafb920] [c000000000024a34] timer_interrupt+0x94/0xe0
[ 4000.060782] [c000000fefafb950] [c00000000000b6e0] restore_check_irq_replay+0x54/0x70
[ 4000.060787] --- interrupt: 901 at lock_timer_base+0x70/0x100
                   LR = schedule_timeout+0x334/0x420
[ 4000.060788] [c000000fefafbc40] [0000000000000001] 0x1 (unreliable)
[ 4000.060791] [c000000fefafbca0] [c000000000c30a14] schedule_timeout+0x334/0x420
[ 4000.060795] [c000000fefafbd80] [c000000000095bf0] kopald+0x90/0xe0
[ 4000.060798] [c000000fefafbdc0] [c0000000001214cc] kthread+0x1ac/0x1c0
[ 4000.060801] [c000000fefafbe30] [c00000000000b2e8] ret_from_kernel_thread+0x5c/0x74
[ 4000.060802] Instruction dump:
[ 4000.060804] 994d02ba 2fa30000 409e0024 e92d0020 61298000 7d210164 38210020 e8010010
[ 4000.060810] 7c0803a6 4e800020 60420000 4bff3f35 <60000000> 4bffffe4 60420000 e92d0020