On 23/08/2017 09:51, Mathias Nyman wrote: > very likely cause is the more aggressive detection of pci removed xhci hosts > > See commit d9f11ba9f107aa335091ab8d7ba5eea714e46e8b > xhci: Rework how we handle unresponsive or hoptlug removed hosts > > It checks if a xhci register reads returns 0xffffffff and assumes xhci > died in that case. > > Could you add something like the below to check which what is killing the host? > Or a BUG()/WARN() in xhci_hc_died() to get a backtrace of who called it. [ 46.525247] usb 2-2: new SuperSpeed USB device number 2 using xhci_hcd [ 46.565496] usb-storage 2-2:1.0: USB Mass Storage device detected [ 46.571934] scsi host0: usb-storage 2-2:1.0 [ 47.601227] scsi 0:0:0:0: Direct-Access Kingston DataTraveler 3.0 PQ: 0 ANSI: 6 [ 47.611340] sd 0:0:0:0: [sda] 15109516 512-byte logical blocks: (7.74 GB/7.20 GiB) [ 47.621624] sd 0:0:0:0: [sda] Write Protect is off [ 47.627131] sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 47.639637] sda: sda1 [ 47.648091] sd 0:0:0:0: [sda] Attached SCSI removable disk [ 58.100306] xhci_hcd 0000:01:00.0: xHCI host controller not responding, assume dead [ 58.108021] CPU: 0 PID: 939 Comm: kworker/0:2 Tainted: G C 4.13.0-rc6 #11 [ 58.115976] Hardware name: Sigma Tango DT [ 58.120016] Workqueue: usb_hub_wq hub_event [ 58.124241] [<c010f288>] (unwind_backtrace) from [<c010af58>] (show_stack+0x10/0x14) [ 58.132033] [<c010af58>] (show_stack) from [<c049d714>] (dump_stack+0x84/0x98) [ 58.139302] [<c049d714>] (dump_stack) from [<c03b090c>] (xhci_hc_died.part.9+0x50/0x23c) [ 58.147438] [<c03b090c>] (xhci_hc_died.part.9) from [<c03b5d80>] (xhci_hub_control+0xf3c/0x175c) [ 58.156273] [<c03b5d80>] (xhci_hub_control) from [<c03934a4>] (usb_hcd_submit_urb+0x264/0x814) [ 58.164932] [<c03934a4>] (usb_hcd_submit_urb) from [<c0394fa4>] (usb_start_wait_urb+0x4c/0xbc) [ 58.173591] [<c0394fa4>] (usb_start_wait_urb) from [<c03950b4>] (usb_control_msg+0xa0/0xcc) [ 58.181985] [<c03950b4>] (usb_control_msg) from [<c038bf54>] (usb_clear_port_feature+0x44/0x4c) [ 58.190730] [<c038bf54>] (usb_clear_port_feature) from [<c038c320>] (hub_port_reset+0x228/0x51c) [ 58.199561] [<c038c320>] (hub_port_reset) from [<c038fd68>] (hub_event+0x87c/0x108c) [ 58.207349] [<c038fd68>] (hub_event) from [<c012ecc4>] (process_one_work+0x1d8/0x3f0) [ 58.215220] [<c012ecc4>] (process_one_work) from [<c012f8d8>] (worker_thread+0x38/0x554) [ 58.223354] [<c012f8d8>] (worker_thread) from [<c01347d0>] (kthread+0x108/0x138) [ 58.230789] [<c01347d0>] (kthread) from [<c01076d8>] (ret_from_fork+0x14/0x3c) [ 58.238056] xhci_hcd 0000:01:00.0: HC died; cleaning up [ 58.243391] usb 2-2: USB disconnect, device number 2
