Hello, There is an issue found on v6.6.16: Plug in thunderbolt G4 dock with monitor connected after system boots up. The monitor shows nothing when wake up from S3 sometimes. The failure rate is above 50%. The kernel reports “UBSAN: shift-out-of-bounds in drivers/gpu/drm/display/drm_dp_mst_topology.c:4416:36”. The call stack is shown at the bottom of this email. This failure is fixed in v6.9-rc1. We request to merge below commit to v6.6. 6b8ac54f31f985d3abb0b4212187838dd8ea4227 thunderbolt: Fix debug log when DisplayPort adapter not available for pairing fe8a0293c922ee8bc1ff0cf9048075afb264004a thunderbolt: Use tb_tunnel_dbg() where possible to make logging more consistent d27bd2c37d4666bce25ec4d9ac8c6b169992f0f0 thunderbolt: Expose tb_tunnel_xxx() log macros to the rest of the driver 8648c6465c025c488e2855c209c0dea1a1a15184 thunderbolt: Create multiple DisplayPort tunnels if there are more DP IN/OUT pairs f73edddfa2a64a185c65a33f100778169c92fc25 thunderbolt: Use constants for path weight and priority 4d24db0c801461adeefd7e0bdc98c79c60ccefb0 thunderbolt: Use weight constants in tb_usb3_consumed_bandwidth() aa673d606078da36ebc379f041c794228ac08cb5 thunderbolt: Make is_gen4_link() available to the rest of the driver 582e70b0d3a412d15389a3c9c07a44791b311715 thunderbolt: Change bandwidth reservations to comply USB4 v2 2bfeca73e94567c1a117ca45d2e8a25d63e5bd2c thunderbolt: Introduce tb_port_path_direction_downstream() 956c3abe72fb6a651b8cf77c28462f7e5b6a48b1 thunderbolt: Introduce tb_for_each_upstream_port_on_path() c4ff14436952c3d0dd05769d76cf48e73a253b48 thunderbolt: Introduce tb_switch_depth() 81af2952e60603d12415e1a6fd200f8073a2ad8b thunderbolt: Add support for asymmetric link 3e36528c1127b20492ffaea53930bcc3df46a718 thunderbolt: Configure asymmetric link if needed and bandwidth allows b4734507ac55cc7ea1380e20e83f60fcd7031955 thunderbolt: Improve DisplayPort tunnel setup process to be more robust When failure happened, the kernel log reports Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414673] UBSAN: shift-out-of-bounds in drivers/gpu/drm/display/drm_dp_mst_topology.c:4416:36 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414674] shift exponent -1 is negative Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414675] CPU: 0 PID: 145 Comm: kworker/0:2 Tainted: G U 6.6.16 #108 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414677] Hardware name: HP HP Elite t660 Thin Client/8D05, BIOS W44 Ver. 00.14.00 07/19/2024 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414678] Workqueue: events output_poll_execute [drm_kms_helper] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414695] Call Trace: Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414697] <TASK> Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414698] dump_stack_lvl+0x48/0x70 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414703] dump_stack+0x10/0x20 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414705] __ubsan_handle_shift_out_of_bounds+0x156/0x310 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414708] ? krealloc+0x98/0x100 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414711] ? drm_atomic_get_private_obj_state+0x167/0x1a0 [drm] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414733] drm_dp_atomic_release_time_slots.cold+0x17/0x3d [drm_display_helper] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414743] intel_dp_mst_atomic_check+0x9a/0x170 [i915] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414831] drm_atomic_helper_check_modeset+0x4bb/0xe20 [drm_kms_helper] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414842] ? __kmem_cache_alloc_node+0x1b3/0x320 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414845] ? __ww_mutex_lock.constprop.0+0x39/0xa00 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414848] intel_atomic_check+0x113/0x2b50 [i915] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414936] drm_atomic_check_only+0x692/0xb80 [drm] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414956] drm_atomic_commit+0x57/0xd0 [drm] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414972] ? _pfx__drm_printfn_info+0x10/0x10 [drm] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.414999] drm_client_modeset_commit_atomic+0x1f1/0x230 [drm] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415019] drm_client_modeset_commit_locked+0x5b/0x170 [drm] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415038] ? mutex_lock+0x13/0x50 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415040] drm_client_modeset_commit+0x27/0x50 [drm] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415058] __drm_fb_helper_restore_fbdev_mode_unlocked+0xd2/0x100 [drm_kms_helper] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415068] drm_fb_helper_hotplug_event+0x11a/0x140 [drm_kms_helper] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415077] intel_fbdev_output_poll_changed+0x6f/0xb0 [i915] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415156] output_poll_execute+0x23e/0x290 [drm_kms_helper] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415166] ? intelfb_dirty+0x41/0x80 [i915] Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415236] process_one_work+0x178/0x360 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415238] ? __pfx_worker_thread+0x10/0x10 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415240] worker_thread+0x307/0x430 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415241] ? __pfx_worker_thread+0x10/0x10 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415242] kthread+0xf4/0x130 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415245] ? __pfx_kthread+0x10/0x10 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415247] ret_from_fork+0x43/0x70 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415249] ? __pfx_kthread+0x10/0x10 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415250] ret_from_fork_asm+0x1b/0x30 Sep 6 08:10:29 HP7c5758fc4d4f kernel: [ 89.415252] </TASK> Thanks, Wanqin
