rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=29265, q=902 ncpus=2)
task:kworker/0:0     state:R  running task     stack:20488 pid:9     tgid:9     ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events request_firmware_work_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x1709/0x5530 kernel/sched/core.c:7231
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7553
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_release+0x2e1/0x3c0 kernel/locking/lockdep.c:5932
Code: f4 21 11 00 00 00 00 eb b5 e8 bb f2 ae 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 8b ae 21 11 48 3b 44 24 28 75 48 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d f8 a4 32
RSP: 0018:ffffc900000e7820 EFLAGS: 00000282
RAX: 6eb8400bdda09000 RBX: 0000000000000206 RCX: 0000000000000046
RDX: 000000007e92a73b RSI: ffffffff8dbfaa0e RDI: ffffffff8bcbd080
RBP: ffff88801de96a50 R08: 1c00000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8e3c3880 R12: 0000000000000004
R13: 0000000000000004 R14: ffff88813fe36d58 R15: ffff88801de95dc0
 rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80
 spin_unlock_irqrestore include/linux/spinlock_rt.h:129 [inline]
 __slab_free+0x236/0x2a0 mm/slub.c:5736
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4608 [inline]
 slab_alloc_node mm/slub.c:4921 [inline]
 __kmalloc_cache_noprof+0x34b/0x670 mm/slub.c:5482
 _kmalloc_noprof include/linux/slab.h:969 [inline]
 _kzalloc_noprof include/linux/slab.h:1290 [inline]
 ath9k_hif_usb_alloc_reg_in_urbs drivers/net/wireless/ath/ath9k/hif_usb.c:965 [inline]
 ath9k_hif_usb_alloc_urbs+0xb06/0x10a0 drivers/net/wireless/ath/ath9k/hif_usb.c:1038
 ath9k_hif_usb_dev_init drivers/net/wireless/ath/ath9k/hif_usb.c:1124 [inline]
 ath9k_hif_usb_firmware_cb+0x123/0x4b0 drivers/net/wireless/ath/ath9k/hif_usb.c:1252
 request_firmware_work_func+0xf7/0x2d0 drivers/base/firmware_loader/main.c:1164
 process_one_work+0xaaf/0x1480 kernel/workqueue.c:3379
 process_scheduled_works kernel/workqueue.c:3462 [inline]
 worker_thread+0xb05/0x10d0 kernel/workqueue.c:3543
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>