Control: tags -1 + moreinfo Hi Matt,
On Tue, Dec 09, 2025 at 10:33:24AM -0800, Matt Marjanovic wrote: > Package: src:linux > Version: 6.12.57-1 > Followup-For: Bug #1054514 > > Dear Maintainer, > > This is back in trixie --- unsurprisingly, because the kernel commit which > had originally caused this bug, and was subsequently reverted, was reapplied > to the kernel in 6.8.10: > > https://www.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.8.10 > (Reapply "drm/qxl: simplify qxl_fence_wait") > > In addition to making the remote graphics freeze (which is annoying but > tolerable), the graphics driver hang also appears to cause systemd tasks > to hang... which leads to problems with remote login via ssh, and also > the inability to do a clean reboot/shutdown (which is intolerable). > > Sample of the kernel log for hung systemd task (bookended by the telltale > "Buffer eviction failed" every 15 seconds): > > [413120.319715] INFO: task systemd:1 blocked for more than 1208 seconds. > [413120.319718] Not tainted 6.12.57+deb13-amd64 #1 Debian 6.12.57-1 > [413120.319719] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables > this message. > [413120.319720] task:systemd state:D stack:0 pid:1 tgid:1 > ppid:0 flags:0x00000002 > [413120.319723] Call Trace: > [413120.319724] <TASK> > [413120.319726] __schedule+0x505/0xc00 > [413120.319730] schedule+0x27/0xf0 > [413120.319732] schedule_preempt_disabled+0x15/0x30 > [413120.319733] __ww_mutex_lock.constprop.0+0x4f6/0x9a0 > [413120.319736] drm_modeset_lock+0x42/0xe0 [drm] > [413120.319765] drm_atomic_get_plane_state+0x7f/0x180 [drm] > [413120.319777] drm_client_modeset_commit_atomic+0xbf/0x250 [drm] > [413120.319793] ? do_sys_poll+0x4e1/0x600 > [413120.319796] drm_client_modeset_commit_locked+0x5a/0x160 [drm] > [413120.319810] drm_fb_helper_pan_display+0xf2/0x240 [drm_kms_helper] > [413120.319819] fb_pan_display+0x89/0x140 > [413120.319821] bit_update_start+0x1e/0x40 > [413120.319822] fbcon_switch+0x421/0x5b0 > [413120.319825] csi_J+0x286/0x2d0 > [413120.319826] do_con_write+0x1368/0x2440 > [413120.319828] ? tomoyo_path_number_perm+0x8c/0x1f0 > [413120.319830] ? _prb_read_valid+0x298/0x310 > [413120.319832] con_write+0x13/0x50 > [413120.319833] n_tty_write+0x15a/0x500 > [413120.319835] ? __pfx_woken_wake_function+0x10/0x10 > [413120.319837] file_tty_write.isra.0+0x172/0x2c0 > [413120.319840] vfs_write+0x28c/0x440 > [413120.319842] ksys_write+0x6d/0xf0 > [413120.319844] do_syscall_64+0x82/0x190 > [413120.319845] ? tty_ioctl+0x145/0x8a0 > [413120.319847] ? arch_exit_to_user_mode_prepare.isra.0+0x16/0xa0 > [413120.319850] ? syscall_exit_to_user_mode+0x37/0x1b0 > [413120.319851] ? do_syscall_64+0x8e/0x190 > [413120.319852] ? do_sys_openat2+0x9c/0xe0 > [413120.319853] ? do_syscall_64+0x8e/0x190 > [413120.319854] ? arch_exit_to_user_mode_prepare.isra.0+0x16/0xa0 > [413120.319856] ? syscall_exit_to_user_mode+0x37/0x1b0 > [413120.319857] ? do_syscall_64+0x8e/0x190 > [413120.319858] ? __x64_sys_ppoll+0xf4/0x160 > [413120.319859] ? arch_exit_to_user_mode_prepare.isra.0+0x16/0xa0 > [413120.319861] ? syscall_exit_to_user_mode+0x37/0x1b0 > [413120.319862] ? do_syscall_64+0x8e/0x190 > [413120.319862] ? clear_bhb_loop+0x40/0x90 > [413120.319864] ? clear_bhb_loop+0x40/0x90 > [413120.319865] ? clear_bhb_loop+0x40/0x90 > [413120.319866] entry_SYSCALL_64_after_hwframe+0x76/0x7e > [413120.319869] RIP: 0033:0x7f38ba499687 > [413120.319878] RSP: 002b:00007ffd7e321560 EFLAGS: 00000202 ORIG_RAX: > 0000000000000001 > [413120.319879] RAX: ffffffffffffffda RBX: 00007f38baa3ee00 RCX: > 00007f38ba499687 > [413120.319880] RDX: 000000000000000c RSI: 00007f38ba927cc4 RDI: > 0000000000000025 > [413120.319881] RBP: 0000000000000025 R08: 0000000000000000 R09: > 0000000000000000 > [413120.319881] R10: 0000000000000000 R11: 0000000000000202 R12: > 00000000000186a0 > [413120.319882] R13: 0000005fe7e4b3fb R14: 000000000000000c R15: > 0000000000000025 > [413120.319883] </TASK> > [413120.319884] Future hung task reports are suppressed, see sysctl > kernel.hung_task_warnings > [413123.903768] [TTM] Buffer eviction failed > [413139.007582] [TTM] Buffer eviction failed > [413154.111473] [TTM] Buffer eviction failed > [413169.215198] [TTM] Buffer eviction failed > [413184.319084] [TTM] Buffer eviction failed > [413199.422894] [TTM] Buffer eviction failed > [413214.526697] [TTM] Buffer eviction failed I guess it is very unlikely that the commit get reverted again, given the reasons explained in the commit message on the re-apply. But can you please confirm that reverting the commit on top of 6.12.y fixes the issue again for you? Note that it has even be re-applied to 6.1.y, actually form 6.9 back to 6.8.10, 6.6.31, 6.1.91 and 5.15.159. Is the issue still as well triggerable in 6.17.11 and mainline? Regards, Salvatore
