Hi All,
While dogfooding 6.0-rc1 on my main workstation I noticed the following
new RCU stall warning/stack trace after a suspend/resume:
[ 290.653114] xhci_hcd 0000:16:00.0: xHC error in resume, USBSTS 0x401, Reinit
...
[ 290.653253] usb usb1: root hub lost power or was reset
[ 290.653255] usb usb2: root hub lost power or was reset
...
[ 290.684960] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 9-...D } 28 jiffies s: 985 root: 0x1/.
[ 290.684972] rcu: blocking rcu_node structures (internal RCU debug): l=1:0-15:0x200/.
[ 290.684975] Task dump for CPU 9:
[ 290.684977] task:kworker/u64:20 state:R running task stack: 0 pid: 3993 ppid: 2 flags:0x00004008
[ 290.684982] Workqueue: events_unbound async_run_entry_fn
[ 290.684987] Call Trace:
[ 290.684988] <TASK>
[ 290.684994] ? lock_is_held_type+0xe3/0x140
[ 290.684999] ? find_held_lock+0x2b/0x80
[ 290.685003] ? lock_release+0x135/0x2d0
[ 290.685008] ? delay_halt+0x3b/0x60
[ 290.685012] ? xhci_handshake+0x3e/0xb0
[ 290.685016] ? xhci_reset+0x6a/0x100
[ 290.685019] ? xhci_resume+0x1ec/0x600
[ 290.685023] ? resume_common+0xa0/0x100
[ 290.685026] ? pci_pm_poweroff_noirq+0x100/0x100
[ 290.685030] ? dpm_run_callback+0x53/0xc0
[ 290.685034] ? device_resume+0xa8/0x200
[ 290.685038] ? async_resume+0x19/0x30
[ 290.685040] ? async_run_entry_fn+0x30/0x130
[ 290.685043] ? process_one_work+0x257/0x570
[ 290.685050] ? worker_thread+0x4f/0x3a0
[ 290.685054] ? process_one_work+0x570/0x570
[ 290.685056] ? kthread+0xf5/0x120
[ 290.685058] ? kthread_complete_and_exit+0x20/0x20
[ 290.685062] ? ret_from_fork+0x22/0x30
[ 290.685072] </TASK>
Note I've not seen any negative side-effects from this yet,
still I thought it would be good to report this.
Regards,
Hans
