------------[ cut here ]------------
bochs-drm 0000:00:01.0: [drm] vblank wait timed out on crtc 0
WARNING: drivers/gpu/drm/drm_vblank.c:1329 at drm_crtc_wait_one_vblank+0x3d5/0x590, CPU#0: kworker/0:5/5669
Modules linked in:
CPU: 0 UID: 0 PID: 5669 Comm: kworker/0:5 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events drm_fb_helper_damage_work
RIP: 0010:drm_crtc_wait_one_vblank+0x53c/0x590
Code: e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 ef e8 94 0d ca fc 4d 8b 7d 00 48 89 df 4c 89 e6 4c 89 fa 44 89 f1 <67> 48 0f b9 3a 48 8b 3c 24 44 89 f6 e8 13 f4 ff ff b8 92 ff ff ff
RSP: 0018:ffffc9000760f920 EFLAGS: 00010246
RAX: 1ffff11020b5381a RBX: ffffffff8f9614c0 RCX: 0000000000000000
RDX: ffff8881046d97a0 RSI: ffffffff8bc24e80 RDI: ffffffff8f9614c0
RBP: ffffc9000760fa08 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f1597f R12: ffffffff8bc24e80
R13: ffff888105a9c0d0 R14: 0000000000000000 R15: ffff8881046d97a0
FS:  0000000000000000(0000) GS:ffff88818e91f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f466c5864f0 CR3: 000000016e2ec000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 drm_client_modeset_wait_for_vblank+0xc5/0xf0
 drm_fb_helper_damage_work+0x131/0x720
 process_one_work+0x98b/0x1630
 worker_thread+0xb8e/0x1140
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
