Am 31.01.19 um 15:56 schrieb Mathias Nyman:
> On 31.01.2019 12:42, Jan-Marek Glogowski wrote:
>> Am 30.01.19 um 17:56 schrieb Jan-Marek Glogowski:
>>> Am 30.01.19 um 15:58 schrieb Mathias Nyman:
>>>> On 30.01.2019 14:38, Jan-Marek Glogowski wrote:
>>>>
>>>> The hub->event bits are set when roothub polling timer function gets data
>>>> from
>>>> hub_status_data(), writes the data to a status urb, and returns the urb.
>>>>
>>>> Normal operation:
>>>> usb_hcd_poll_rh_status() // roothub polling timer function
>>>> hcd->driver->hub_status_data(hcd, buffer) -> xhci_hub_status_data()
>>>> xhci_hub_status_data() //returns buffer with bits set if a port
>>>> needs attention
>>>> if (buffer && urb)
>>>> memcpy(urb->transfer_buffer, buffer) // copy buffer bits to urb
>>>> usb_hcd_giveback_urb(urb) -> hub_irq // calls urb complete
>>>> callback function
>>>> hub_irq()
>>>> hub->event_bits = urb->transfer_buffer //
>>>> mod_timer(usb_hcd_poll_rh_status, future) // reschedule roothub
>>>> polling timer
>>>>
>>>> I'm guessing usb_hcd_poll_rh_status() never properly completes a URB in
>>>> your case.
>>>>
>>>> This could be possible if roothub is polled before properly resumed, then
>>>> the URB wouldn't
>>>> be available yet, and no hub->event_bits are set.
>>>> Because no bits are set the hub starts suspending again after resume,
>>>> probably before roothub
>>>> timer polls roothub again.
>>>> suspend fails when it manually checks hcd->driver->hub_status_data() for
>>>> activity, and
>>>> it start resuming again, and continues this in a loop.
>>>>
>>>> Either roothub polling is stopped at the suspend attempt, or maybe
>>>> continuously rescheduled
>>>> into the future because as a part of suspend attempt/resume loop.
>>
>> So as you expected the status_urb is always NULL.
>>
>> I tried to understand more of the code by adding some more debug message.
>>
>> I looked at usb_hcd_resume_root_hub, which is called when we see the "resume
>> root hub" dmesg.
>> This just queues the hcd->wakeup_work, so indeed, if usb_hcd_poll_rh_status
>> is later called,
>> the hub might not have resumed yet and polling starts. So my simple approach
>> was to add a
>> function to call flush_work(&hcd->wakeup_work) before
>> usb_hcd_poll_rh_status. All variants I
>> tested killed the kernel. I also tried to add a udelay to no avail.
>
> I think the idea is that if usb_hcd_poll_rh_status() finds a port that needs
> attention, but
> the is URB missing, then a HCD_FLAG_POLL_PENDING flag is set.
>
> This flag is checked in resume when submitting the hub URB, and idea is to
> react on it:
>
> hub_activate(HUB_RESUME)
> usb_submit_urb(hub->urb)
> rh_urb_enqueue()
> rh_queue_status()
> hcd->status_urb = urb;
> if (HCD_POLL_PENDING(hcd)
> mod_timer(&hcd->rh_timer, jiffies);
>
> It tries to trigger usb_hcd_poll_rh_status() immediately by modifying the
> timer,
> but from your logs it seems that it's not fast enough:
>
> [ 485.301806] usbcore:hub_resume: hub 2-0:1.0: hub_resume
> [ 485.301819] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
> status, actual port 0 status = 0x2a0
> ...
> [ 485.301936] usbcore:hub_event: hub 2-0:1.0: state 7 ports 6 chg 0000 evt
> 0000
> [ 485.301952] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: set port
> remote wake mask, actual port 0 status = 0xe0002a0
> ...
> [ 485.302034] usbcore:hub_suspend: hub 2-0:1.0: hub_suspend
> [ 485.302048] usbcore:hcd_bus_suspend: usb usb2: bus auto-suspend, wakeup 1
> [ 485.302067] usbcore:hcd_bus_suspend: usb usb2: suspend raced with wakeup
> event
> [ 485.302071] usbcore:hcd_bus_resume: usb usb2: usb auto-resume
> [ 485.309765] usb usb2: usb_hcd_poll_rh_status, length 1, hcd->flags 0x18d,
> status_urb NULL
>
> hcd->flags 0x18d means HCD_FLAG_POLL_PENDING was set, but hub_event()
> workqueue and hub_suspend()
> are run before polling the root hub, and I guess the URB gets removed at some
> point during suspsend.
>
> This then goes on in a loop.
>
> You could try running usb_hcd_poll_rh_status() direcly instead of just
> kicking the timer and see if
> it works:
>
> @@ -822,8 +826,11 @@ static int rh_queue_status (struct usb_hcd *hcd, struct
> urb *urb)
> mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
>
> /* If a status change has already occurred, report it ASAP */
> - else if (HCD_POLL_PENDING(hcd))
> - mod_timer(&hcd->rh_timer, jiffies);
> + else if (HCD_POLL_PENDING(hcd)) {
> + spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
> + usb_hcd_poll_rh_status(hcd);
> + return 0;
> + }
> retval = 0;
> done:
> spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
>
>
> I didn't check locking or running contexts if it's ok to do this, there's
> could be a reason
> why it wasn't done like this in the first place.
> Worth a shot still.
Yup - that also works. That still has the first status_urb NULL and one resume
-> suspend race.
I just kept your dev_err in addition.
[18818.679289] xhci_hcd:handle_port_status: xhci_hcd 0000:00:14.0: Port Status
Change Event for port 20
[18818.679299] xhci_hcd:handle_port_status: xhci_hcd 0000:00:14.0: resume root
hub
[18818.679314] xhci_hcd:handle_port_status: xhci_hcd 0000:00:14.0:
handle_port_status: starting port polling.
[18818.679329] usb usb2: usb_hcd_poll_rh_status, length 1, hcd->flags 0x195,
status_urb NULL
[18818.679387] usbcore:usb_remote_wakeup: usb usb2: usb wakeup-resume
[18818.679395] usbcore:hcd_bus_resume: usb usb2: usb auto-resume
[18818.679416] usbcore:hub_resume: hub 2-0:1.0: hub_resume
[18818.679428] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 0 status = 0x2a0
[18818.679439] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x2a0
[18818.679476] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 1 status = 0x2a0
[18818.679485] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x2a0
[18818.679499] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 2 status = 0x2a0
[18818.679503] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x2a0
[18818.679518] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x4002c0
[18818.679522] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x4002c0
[18818.679538] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 4 status = 0x2a0
[18818.679546] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x2a0
[18818.679561] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 5 status = 0x2a0
[18818.679565] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x2a0
[18818.679586] usb usb2: usb_hcd_poll_rh_status, length 1, hcd->flags 0x1ad,
status_urb Exists
[18818.679602] usbcore:hub_event: hub 2-0:1.0: state 7 ports 6 chg 0000 evt 0000
[18818.679619] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: set port
remote wake mask, actual port 0 status = 0xe0002a0
[18818.679645] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: set port
remote wake mask, actual port 1 status = 0xe0002a0
[18818.679659] usbcore:hub_event: hub 2-0:1.0: state 7 ports 6 chg 0000 evt 0010
[18818.679677] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: set port
remote wake mask, actual port 2 status = 0xe0002a0
[18818.679695] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: set port
remote wake mask, actual port 3 status = 0xe4002c0
[18818.679712] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: set port
remote wake mask, actual port 4 status = 0xe0002a0
[18818.679729] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: set port
remote wake mask, actual port 5 status = 0xe0002a0
[18818.679744] usbcore:hub_suspend: hub 2-0:1.0: hub_suspend
[18818.679762] usbcore:hcd_bus_suspend: usb usb2: bus auto-suspend, wakeup 1
[18818.679784] usbcore:hcd_bus_suspend: usb usb2: suspend raced with wakeup
event
[18818.679789] usbcore:hcd_bus_resume: usb usb2: usb auto-resume
[18818.698146] usbcore:hub_resume: hub 2-0:1.0: hub_resume
[18818.698159] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 0 status = 0x2a0
[18818.698164] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x2a0
[18818.698188] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 1 status = 0x2a0
[18818.698192] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x2a0
[18818.698206] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 2 status = 0x2a0
[18818.698210] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x2a0
[18818.698224] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x4002c0
[18818.698229] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x4002c0
[18818.698243] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 4 status = 0x2a0
[18818.698247] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x2a0
[18818.698263] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 5 status = 0x2a0
[18818.698268] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x2a0
[18818.698294] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x4002c0
[18818.698298] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x4002c0
[18818.698310] usbcore:port_event: usb usb2-port4: link state change
[18818.698320] xhci_hcd:xhci_clear_port_change_bit: xhci_hcd 0000:00:14.0:
clear port link state change, actual port 3 status = 0x2c0
[18818.698330] usbcore:port_event: usb usb2-port4: do warm reset
[18818.758189] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x2b0
[18818.758195] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x2b0
[18818.758222] usbcore:hub_port_wait_reset: usb usb2-port4: not warm reset yet,
waiting 50ms
[18818.762303] xhci_hcd:xhci_hub_status_data: xhci_hcd 0000:00:14.0:
xhci_hub_status_data: stopping port polling.
[18818.762312] usb usb2: usb_hcd_poll_rh_status, length 0, hcd->flags 0x1a1,
status_urb Exists
[18818.804070] xhci_hcd:handle_port_status: xhci_hcd 0000:00:14.0: Port Status
Change Event for port 20
[18818.804080] xhci_hcd:handle_port_status: xhci_hcd 0000:00:14.0:
handle_port_status: starting port polling.
[18818.804095] usb usb2: usb_hcd_poll_rh_status, length 1, hcd->flags 0x1a5,
status_urb Exists
[18818.818339] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x2a1203
[18818.818345] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x310203
[18818.818387] xhci_hcd:xhci_clear_port_change_bit: xhci_hcd 0000:00:14.0:
clear port reset change, actual port 3 status = 0xa1203
[18818.818404] xhci_hcd:xhci_clear_port_change_bit: xhci_hcd 0000:00:14.0:
clear port warm(BH) reset change, actual port 3 status = 0x21203
[18818.818422] xhci_hcd:xhci_clear_port_change_bit: xhci_hcd 0000:00:14.0:
clear port link state change, actual port 3 status = 0x21203
[18818.818435] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x21203
[18818.818439] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x10203
[18818.878337] usbcore:hub_event: hub 2-0:1.0: state 7 ports 6 chg 0000 evt 0010
[18818.878355] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x21203
[18818.878360] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x10203
[18818.878392] xhci_hcd:xhci_clear_port_change_bit: xhci_hcd 0000:00:14.0:
clear port connect change, actual port 3 status = 0x1203
[18818.878406] usbcore:hub_port_connect_change: usb usb2-port4: status 0203,
change 0001, 10.0 Gb/s
[18818.878414] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x1203
[18818.878418] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x203
[18818.914324] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x1203
[18818.914330] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x203
[18818.950175] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x1203
[18818.950181] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x203
[18818.986348] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x1203
[18818.986354] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x203
[18819.010300] xhci_hcd:xhci_hub_status_data: xhci_hcd 0000:00:14.0:
xhci_hub_status_data: stopping port polling.
[18819.010309] usb usb2: usb_hcd_poll_rh_status, length 0, hcd->flags 0x1a1,
status_urb Exists
[18819.022316] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x1203
[18819.022322] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x203
[18819.022349] usbcore:hub_port_debounce: usb usb2-port4: debounce total 100ms
stable 100ms status 0x203
[18819.022360] xhci_hcd:xhci_ring_cmd_db: xhci_hcd 0000:00:14.0: // Ding dong!
[18819.022457] xhci_hcd:xhci_alloc_virt_device: xhci_hcd 0000:00:14.0: Slot 1
output ctx = 0x44ea02000 (dma)
[18819.022463] xhci_hcd:xhci_alloc_virt_device: xhci_hcd 0000:00:14.0: Slot 1
input ctx = 0x458568000 (dma)
[18819.022475] xhci_hcd:xhci_alloc_virt_device: xhci_hcd 0000:00:14.0: Set slot
id 1 dcbaa entry 0000000095bf5995 to 0x44ea02000
[18819.022522] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x1203
[18819.022526] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x203
[18819.022546] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: set port
reset, actual port 3 status = 0x1311
[18819.022554] xhci_hcd:handle_port_status: xhci_hcd 0000:00:14.0: Port Status
Change Event for port 20
[18819.022559] xhci_hcd:handle_port_status: xhci_hcd 0000:00:14.0:
handle_port_status: starting port polling.
[18819.022572] usb usb2: usb_hcd_poll_rh_status, length 0, hcd->flags 0x1a5,
status_urb Exists
[18819.090325] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x201203
[18819.090331] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x100203
[18819.090366] xhci_hcd:xhci_clear_port_change_bit: xhci_hcd 0000:00:14.0:
clear port reset change, actual port 3 status = 0x1203
[18819.090382] xhci_hcd:xhci_clear_port_change_bit: xhci_hcd 0000:00:14.0:
clear port warm(BH) reset change, actual port 3 status = 0x1203
[18819.090401] xhci_hcd:xhci_clear_port_change_bit: xhci_hcd 0000:00:14.0:
clear port link state change, actual port 3 status = 0x1203
[18819.090415] xhci_hcd:xhci_clear_port_change_bit: xhci_hcd 0000:00:14.0:
clear port connect change, actual port 3 status = 0x1203
[18819.090430] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: get port
status, actual port 3 status = 0x1203
[18819.090434] xhci_hcd:xhci_hub_control: xhci_hcd 0000:00:14.0: Get port
status returned 0x203
[18819.150399] xhci_hcd:xhci_setup_addressable_virt_dev: xhci_hcd 0000:00:14.0:
Set root hub portnum to 20
[18819.150405] xhci_hcd:xhci_setup_addressable_virt_dev: xhci_hcd 0000:00:14.0:
Set fake root hub portnum to 4
[18819.150410] xhci_hcd:xhci_setup_addressable_virt_dev: xhci_hcd 0000:00:14.0:
udev->tt = (null)
[18819.150415] xhci_hcd:xhci_setup_addressable_virt_dev: xhci_hcd 0000:00:14.0:
udev->ttport = 0x0
[18819.150422] xhci_hcd:xhci_ring_cmd_db: xhci_hcd 0000:00:14.0: // Ding dong!
[18819.150479] xhci_hcd:xhci_dbg_trace: xhci_hcd 0000:00:14.0: Successful setup
address command
[18819.150488] xhci_hcd:xhci_dbg_trace: xhci_hcd 0000:00:14.0: Op regs DCBAA
ptr = 0x00000457c1b000
[18819.150495] xhci_hcd:xhci_dbg_trace: xhci_hcd 0000:00:14.0: Slot ID 1 dcbaa
entry @0000000095bf5995 = 0x0000044ea02000
[18819.150500] xhci_hcd:xhci_dbg_trace: xhci_hcd 0000:00:14.0: Output Context
DMA address = 0x44ea02000
[18819.150505] xhci_hcd:xhci_dbg_trace: xhci_hcd 0000:00:14.0: Internal device
address = 0
[18819.150514] usb 2-4: new SuperSpeed Gen 1 USB device number 2 using xhci_hcd
[18819.170820] usbcore:usb_parse_endpoint: usb 2-4: skipped 1 descriptor after
endpoint
[18819.170826] usbcore:usb_parse_endpoint: usb 2-4: skipped 1 descriptor after
endpoint
[18819.170858] xhci_hcd:process_ctrl_td: xhci_hcd 0000:00:14.0: Waiting for
status stage event
[18819.170904] usbcore:usb_get_langid: usb 2-4: default language 0x0409
[18819.170940] xhci_hcd:process_ctrl_td: xhci_hcd 0000:00:14.0: Waiting for
status stage event
[18819.171018] xhci_hcd:process_ctrl_td: xhci_hcd 0000:00:14.0: Waiting for
status stage event
[18819.171098] xhci_hcd:process_ctrl_td: xhci_hcd 0000:00:14.0: Waiting for
status stage event
[18819.171147] usbcore:usb_new_device: usb 2-4: udev 2, busnum 2, minor = 129
[18819.171154] usb 2-4: New USB device found, idVendor=0781, idProduct=5596,
bcdDevice= 1.00
[18819.171159] usb 2-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[18819.171163] usb 2-4: Product: Ultra T C
[18819.171166] usb 2-4: Manufacturer: SanDisk
[18819.171170] usb 2-4: SerialNumber: 4C530001090830111403
[18819.171397] usbcore:usb_probe_device: usb 2-4: usb_probe_device
....
So is your patch a general solution?
Can we get this as a bug fix into the kernel?
Jan-Marek
