Hi,
see [1] for a workaround. Most likely, the vblank timeout is simply
handled too late.
[1]
https://lore.kernel.org/dri-devel/[email protected]/
Best regards
Thomas
Am 23.10.25 um 04:29 schrieb kernel test robot:
Hello,
kernel test robot noticed
"WARNING:at_drivers/gpu/drm/drm_vblank.c:#drm_wait_one_vblank" on:
commit: e485883c815ee908de82547806d6edd65664b77b ("drm/qxl: Use vblank timer")
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
in testcase: trinity
version:
with following parameters:
runtime: 300s
group: group-01
nr_groups: 5
config: x86_64-dcg_x86_64_defconfig-tdx
compiler: gcc-14
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
(please refer to attached dmesg/kmsg for entire log/backtrace)
we noticed the issue happens randomly. 6 times out of 50 runs as below.
but the parent keeps clean.
=========================================================================================
tbox_group/testcase/rootfs/kconfig/compiler/runtime/group/nr_groups:
vm-snb/trinity/yocto-x86_64-minimal-20190520.cgz/x86_64-dcg_x86_64_defconfig-tdx/gcc-14/300s/group-01/5
42dd66d377ccf786 e485883c815ee908de82547806d
---------------- ---------------------------
fail:runs %reproduction fail:runs
| | |
:50 12% 6:50 dmesg.RIP:drm_wait_one_vblank
:50 12% 6:50
dmesg.WARNING:at_drivers/gpu/drm/drm_vblank.c:#drm_wait_one_vblank
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-lkp/[email protected]
[ 256.077310][ T135] ------------[ cut here ]------------
[ 256.078847][ T135] bochs-drm 0000:00:02.0: [drm] vblank wait timed out on
crtc 0
[ 256.080802][ T135] WARNING: CPU: 0 PID: 135 at
drivers/gpu/drm/drm_vblank.c:1320 drm_wait_one_vblank
(drivers/gpu/drm/drm_vblank.c:1320 (discriminator 5))
[ 256.083260][ T135] Modules linked in: 8021q bridge stp llc nfc pppoe pppox
ppp_generic slhc crypto_user ib_core nfnetlink scsi_transport_iscsi xfrm_user
sctp ip6_udp_tunnel udp_tunnel uvesafb sr_mod cdrom intel_rapl_msr joydev ppdev
ata_generic pata_acpi intel_rapl_common psmouse i2c_piix4 serio_raw bochs
drm_shmem_helper ata_piix i2c_smbus parport_pc parport
[ 256.094913][ T135] CPU: 0 UID: 0 PID: 135 Comm: kworker/0:4 Not tainted
6.18.0-rc1-00240-ge485883c815e #1 PREEMPT(none)
[ 256.097761][ T135] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 256.100575][ T135] Workqueue: events drm_fb_helper_damage_work
[ 256.102578][ T135] RIP: 0010:drm_wait_one_vblank
(drivers/gpu/drm/drm_vblank.c:1320 (discriminator 5))
[ 256.104543][ T135] Code: 00 4d 8b 75 50 4d 85 f6 0f 84 5e 01 00 00 4c 89 ef e8 8d
eb 74 00 89 e9 4c 89 f2 48 c7 c7 60 0b c6 a2 48 89 c6 e8 e9 d1 e2 fd <0f> 0b e9
9a fe ff ff 48 85 db 74 23 48 b8 00 00 00 00 00 fc ff df
All code
========
0: 00 4d 8b add %cl,-0x75(%rbp)
3: 75 50 jne 0x55
5: 4d 85 f6 test %r14,%r14
8: 0f 84 5e 01 00 00 je 0x16c
e: 4c 89 ef mov %r13,%rdi
11: e8 8d eb 74 00 call 0x74eba3
16: 89 e9 mov %ebp,%ecx
18: 4c 89 f2 mov %r14,%rdx
1b: 48 c7 c7 60 0b c6 a2 mov $0xffffffffa2c60b60,%rdi
22: 48 89 c6 mov %rax,%rsi
25: e8 e9 d1 e2 fd call 0xfffffffffde2d213
2a:* 0f 0b ud2 <-- trapping instruction
2c: e9 9a fe ff ff jmp 0xfffffffffffffecb
31: 48 85 db test %rbx,%rbx
34: 74 23 je 0x59
36: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
3d: fc ff df
Code starting with the faulting instruction
===========================================
0: 0f 0b ud2
2: e9 9a fe ff ff jmp 0xfffffffffffffea1
7: 48 85 db test %rbx,%rbx
a: 74 23 je 0x2f
c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
13: fc ff df
[ 256.109982][ T135] RSP: 0018:ffffc9000079fb78 EFLAGS: 00010282
[ 256.112311][ T135] RAX: 0000000000000000 RBX: ffff88815e2c0000 RCX:
0000000000000000
[ 256.114875][ T135] RDX: 0000000000000000 RSI: 0000000000000004 RDI:
0000000000000001
[ 256.117530][ T135] RBP: 0000000000000000 R08: 0000000000000000 R09:
fffffbfff476a008
[ 256.120090][ T135] R10: 0000000000000003 R11: 0000000000000001 R12:
1ffff920000f3f70
[ 256.122749][ T135] R13: ffff88810fe460c8 R14: ffff88810be64d00 R15:
ffff88815cfb2830
[ 256.125298][ T135] FS: 0000000000000000(0000) GS:ffff888408834000(0000)
knlGS:0000000000000000
[ 256.131615][ T135] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 256.135805][ T135] CR2: 000000000109a850 CR3: 000000016d2a0000 CR4:
00000000000406f0
[ 256.137327][ T135] Call Trace:
[ 256.145896][ T135] <TASK>
[ 256.147603][ T135] ? __pfx_drm_wait_one_vblank
(drivers/gpu/drm/drm_vblank.c:1301)
[ 256.149778][ T135] ? __pfx_autoremove_wake_function
(kernel/sched/wait.c:402)
[ 256.153665][ T135] ? do_raw_spin_unlock (arch/x86/include/asm/atomic.h:23
include/linux/atomic/atomic-arch-fallback.h:457
include/linux/atomic/atomic-instrumented.h:33
include/asm-generic/qspinlock.h:57 kernel/locking/spinlock_debug.c:101
kernel/locking/spinlock_debug.c:141)
[ 256.157616][ T135] ? _raw_spin_unlock_irqrestore
(include/linux/spinlock_api_smp.h:152 (discriminator 3)
kernel/locking/spinlock.c:194 (discriminator 3))
[ 256.165734][ T135] drm_client_modeset_wait_for_vblank
(drivers/gpu/drm/drm_client_modeset.c:1331)
[ 256.172077][ T135] drm_fb_helper_fb_dirty
(drivers/gpu/drm/drm_fb_helper.c:373)
[ 256.177086][ T135] ? do_raw_spin_lock (arch/x86/include/asm/atomic.h:107
include/linux/atomic/atomic-arch-fallback.h:2170
include/linux/atomic/atomic-instrumented.h:1302
include/asm-generic/qspinlock.h:111 kernel/locking/spinlock_debug.c:116)
[ 256.181829][ T135] ? __pfx_drm_fb_helper_fb_dirty
(drivers/gpu/drm/drm_fb_helper.c:364)
[ 256.187127][ T135] ? __pfx_do_raw_spin_lock
(kernel/locking/spinlock_debug.c:114)
[ 256.192329][ T135] process_one_work (arch/x86/include/asm/atomic.h:23
include/linux/atomic/atomic-arch-fallback.h:457 include/linux/jump_label.h:262
include/trace/events/workqueue.h:110 kernel/workqueue.c:3268)
[ 256.197045][ T135] worker_thread (kernel/workqueue.c:3340 (discriminator
2) kernel/workqueue.c:3427 (discriminator 2))
[ 256.201991][ T135] ? __kthread_parkme (arch/x86/include/asm/bitops.h:202
(discriminator 1) arch/x86/include/asm/bitops.h:232 (discriminator 1)
include/asm-generic/bitops/instrumented-non-atomic.h:142 (discriminator 1)
kernel/kthread.c:290 (discriminator 1))
[ 256.206956][ T135] ? __pfx_worker_thread (kernel/workqueue.c:3373)
[ 256.216519][ T135] ? __pfx_worker_thread (kernel/workqueue.c:3373)
[ 256.220825][ T135] kthread (kernel/kthread.c:463)
[ 256.224107][ T135] ? __pfx_kthread (kernel/kthread.c:412)
[ 256.229092][ T135] ? __pfx_kthread (kernel/kthread.c:412)
[ 256.233881][ T135] ? __pfx_kthread (kernel/kthread.c:412)
[ 256.239125][ T135] ret_from_fork (arch/x86/kernel/process.c:164)
[ 256.244094][ T135] ? __pfx_kthread (kernel/kthread.c:412)
[ 256.248707][ T135] ret_from_fork_asm (arch/x86/entry/entry_64.S:255)
[ 256.254397][ T135] </TASK>
[ 256.260599][ T135] ---[ end trace 0000000000000000 ]---
[ 349.555954][ T346] sh: can't kill pid 3589: No such process
LKP: ttyS0: 304: LKP: rebooting forcely
[ 359.020039][ T304] sysrq: Emergency Sync
[ 359.022624][ T9] Emergency Sync complete
[ 359.032291][ T304] sysrq: Resetting
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20251022/[email protected]
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
