Re: [syzbot] WARNING in drm_wait_one_vblank

[syzbot <syzbot+6f7fe2dbc479dca0ed17@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in drm_wait_one_vblank

platform vkms: vblank wait timed out on crtc 0
WARNING: CPU: 1 PID: 4329 at drivers/gpu/drm/drm_vblank.c:1269 drm_wait_one_vblank+0x2bc/0x500 drivers/gpu/drm/drm_vblank.c:1269
Modules linked in:

CPU: 1 PID: 4329 Comm: syz-executor.5 Not tainted 6.1.0-rc8-syzkaller-00148-g0d1409e4ff08 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:drm_wait_one_vblank+0x2bc/0x500 drivers/gpu/drm/drm_vblank.c:1269
Code: 85 f6 0f 84 a3 01 00 00 e8 a1 82 03 fd 4c 89 ef e8 19 34 1b 00 44 89 e1 4c 89 f2 48 c7 c7 80 67 5d 8a 48 89 c6 e8 1b 54 d1 04 <0f> 0b e9 87 fe ff ff e8 78 82 03 fd 31 ff 4c 89 ee e8 5e 7f 03 fd
RSP: 0018:ffffc90003887b40 EFLAGS: 00010282

RAX: 0000000000000000 RBX: 000000000000187a RCX: 0000000000000000
RDX: ffff888077e56080 RSI: ffffffff81615618 RDI: fffff52000710f5a
RBP: ffff888146b6c000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88801e146010 R14: ffff888146fb2dc0 R15: ffff888146ffe030
FS:  00007fd446839700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d58fce0300 CR3: 0000000066c1d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 drm_fb_helper_ioctl+0x159/0x1a0 drivers/gpu/drm/drm_fb_helper.c:1259
 do_fb_ioctl+0x1d5/0x6e0 drivers/video/fbdev/core/fbmem.c:1188
 fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1202
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fd445689409
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd446839168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd44579bf80 RCX: 00007fd445689409
RDX: 0000000000000000 RSI: 0000000040044620 RDI: 0000000000000003
RBP: 00007fd4468391d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffff493021f R14: 00007fd446839300 R15: 0000000000022000
 </TASK>


Tested on:

commit:         0d1409e4 Merge tag 'drm-fixes-2022-12-09' of git://ano..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=10bf8cb7880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f99d4932d068617a
dashboard link: https://syzkaller.appspot.com/bug?extid=6f7fe2dbc479dca0ed17
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Note: no patches were applied.