* Lowspeed USB device enumerationg under 5.4.288, but not under 6.8.1
@ 2026-04-02 15:34 Fischer, Simon
2026-04-02 16:10 ` Greg KH
2026-05-06 6:58 ` Michal Pecio
0 siblings, 2 replies; 8+ messages in thread
From: Fischer, Simon @ 2026-04-02 15:34 UTC (permalink / raw)
To: regressions@lists.linux.dev
Dear list,
I've tried to dig deeper into the issues, tried different quirks and small patches, but was unable to solve this or find the root cause. As this seems to be a regression of 6.8 from 5.4, I hope this is the correct list?
I got setup with a low speed isochronous USB device (Optec filter wheel), that is connected to a Dell R6515 server via a Lindy 300m 2 Port Fibre Optic USB 3.0 Extender (which enumerates as a chain of USB3 super speed hubs).
The server is running Ubuntu 24.04 with a 6.8.1 RT kernel. When connecting the device, it fails to enumerate:
[ 1843.938804] usb 2-1.2.1: new SuperSpeed USB device number 14 using xhci_hcd
[ 1843.950893] xhci_hcd 0000:04:00.3: Waiting for status stage event
[ 1843.950937] xhci_hcd 0000:04:00.3: Waiting for status stage event
[ 1843.950981] xhci_hcd 0000:04:00.3: Waiting for status stage event
[ 1843.950998] usb 2-1.2.1: New USB device found, idVendor=0424, idProduct=7016, bcdDevice= 6.26
[ 1843.951006] usb 2-1.2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 1843.951013] usb 2-1.2.1: Product: USB7016 Smart Hub
[ 1843.951018] usb 2-1.2.1: Manufacturer: Microchip
[ 1843.951365] xhci_hcd 0000:04:00.3: add ep 0x81, slot id 4, new drop flags = 0x0, new add flags = 0x8
[ 1843.951375] xhci_hcd 0000:04:00.3: xhci_check_bandwidth called for udev 00000000f628da0a
[ 1843.951387] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1843.952768] xhci_hcd 0000:04:00.3: Successful Endpoint Configure command
[ 1843.952825] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1843.952865] xhci_hcd 0000:04:00.3: Stopped on No-op or Link TRB for slot 4 ep 2
[ 1843.952884] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1843.969034] hub 2-1.2.1:1.0: USB hub found
[ 1843.969108] hub 2-1.2.1:1.0: 3 ports detected
[ 1843.969459] xhci_hcd 0000:04:00.3: xHCI version 110 needs hub TT think time and number of ports
[ 1843.969466] xhci_hcd 0000:04:00.3: Set up configure endpoint for hub device.
[ 1843.969474] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1843.969529] xhci_hcd 0000:04:00.3: Successful Endpoint Configure command
[ 1844.178598] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1844.178634] xhci_hcd 0000:04:00.3: Slot 5 output ctx = 0x0x0000000179f5f000 (dma)
[ 1844.178643] xhci_hcd 0000:04:00.3: Slot 5 input ctx = 0x0x00000001311ce000 (dma)
[ 1844.178652] xhci_hcd 0000:04:00.3: Set slot id 5 dcbaa entry 00000000bb87fc6b to 0x179f5f000
[ 1844.208850] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.224776] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.240774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.242544] xhci_hcd 0000:04:00.3: Set root hub portnum to 3
[ 1844.242554] xhci_hcd 0000:04:00.3: Set fake root hub portnum to 1
[ 1844.242560] xhci_hcd 0000:04:00.3: udev->tt = 0000000000000000
[ 1844.242565] xhci_hcd 0000:04:00.3: udev->ttport = 0x0
[ 1844.242573] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1844.250778] usb 2-1.2.1.3: Device not responding to setup address.
[ 1844.250888] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1844.250919] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1844.250959] xhci_hcd 0000:04:00.3: Slot 5 output ctx = 0x0x0000000179f5f000 (dma)
[ 1844.250968] xhci_hcd 0000:04:00.3: Slot 5 input ctx = 0x0x00000001311ce000 (dma)
[ 1844.250976] xhci_hcd 0000:04:00.3: Set slot id 5 dcbaa entry 00000000bb87fc6b to 0x179f5f000
[ 1844.256773] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.272775] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.288888] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.304774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.320774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.336774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.352774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.368774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.384774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.400774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.416774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.432774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.448774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.458535] xhci_hcd 0000:04:00.3: Set root hub portnum to 3
[ 1844.458544] xhci_hcd 0000:04:00.3: Set fake root hub portnum to 1
[ 1844.458550] xhci_hcd 0000:04:00.3: udev->tt = 0000000000000000
[ 1844.458556] xhci_hcd 0000:04:00.3: udev->ttport = 0x0
[ 1844.458563] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1844.464774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.466663] usb 2-1.2.1.3: Device not responding to setup address.
[ 1844.466771] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1844.466801] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1844.466843] xhci_hcd 0000:04:00.3: Slot 5 output ctx = 0x0x0000000179f5f000 (dma)
[ 1844.466851] xhci_hcd 0000:04:00.3: Slot 5 input ctx = 0x0x00000001311ce000 (dma)
[ 1844.466860] xhci_hcd 0000:04:00.3: Set slot id 5 dcbaa entry 00000000bb87fc6b to 0x179f5f000
[ 1844.480774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.496774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.512774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.528774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.544774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.560774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.576774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.592774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.608776] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.624777] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.640774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.656775] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.672776] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
[ 1844.674524] usb 2-1.2.1.3: device not accepting address 15, error -71
[ 1844.675151] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1844.675178] xhci_hcd 0000:04:00.3: Bad real port.
[ 1844.675188] xhci_hcd 0000:04:00.3: // Ding dong!
[this repeats multiple times until giving up]
[ 1864.698065] usb 2-1.2.1.3.4: device not accepting address 25, error -71
[ 1864.698674] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1864.698711] xhci_hcd 0000:04:00.3: Bad real port.
[ 1864.698718] usb 2-1.2.1.3-port4: unable to enumerate USB device
[ 1864.699443] xhci_hcd 0000:04:00.3: Cancel URB 00000000c8fb420b, dev 1.2.1.3, ep 0x81, starting at offset 0x16e8fb050
[ 1864.699455] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1864.699474] xhci_hcd 0000:04:00.3: Stopped on Transfer TRB for slot 5 ep 2
[ 1864.699481] xhci_hcd 0000:04:00.3: Removing canceled TD starting at 0x16e8fb050 (dma) in stream 0 URB 00000000c8fb420b
[ 1864.699489] xhci_hcd 0000:04:00.3: Set TR Deq ptr 0x16e8fb060, cycle 1
[ 1864.699495] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1864.699500] xhci_hcd 0000:04:00.3: xhci_giveback_invalidated_tds: Keep cancelled URB 00000000c8fb420b TD as cancel_status is 2
[ 1864.699510] xhci_hcd 0000:04:00.3: Successful Set TR Deq Ptr cmd, deq = @16e8fb060
[ 1864.699517] xhci_hcd 0000:04:00.3: xhci_handle_cmd_set_deq: Giveback cancelled URB 00000000c8fb420b TD
[ 1864.699522] xhci_hcd 0000:04:00.3: Giveback URB 00000000c8fb420b, len = 0, expected = 2, status = -115
[ 1864.711179] xhci_hcd 0000:04:00.3: Cancel URB 00000000301149a6, dev 1.2.1, ep 0x81, starting at offset 0x125370300
[ 1864.711194] xhci_hcd 0000:04:00.3: // Ding dong!
[ 1864.711211] xhci_hcd 0000:04:00.3: Stopped on Transfer TRB for slot 4 ep 2
[ 1864.711218] xhci_hcd 0000:04:00.3: Removing canceled TD starting at 0x125370300 (dma) in stream 0 URB 00000000301149a6
[ 1864.711226] xhci_hcd 0000:04:00.3: Set TR Deq ptr 0x125370310, cycle 1
[ 1864.711232] xhci_hcd 0000:04:00.3: // Ding dong!
When booting into a 5.4.288 PREEMPT_RT kernel we were using before with, everything works fine (device enumerates and works).
When exchanging the USB Extender for a Lindy 200m Fibre Optic USB 2.0 Extender, everything works fine with the 6.8.1 kernel.
I cannot inject a USB 2.0 hub before the extender, because it is a super speed device and not compatible.
Any suggestions how to fix or further investigate the issue would be greatly appreciated!
Kind regards
Simon Fischer
Developer
Department E5 - CoDaC
Max Planck Institute for Plasmaphysics
Wendelsteinstrasse 1
17491 Greifswald, Germany
Phone: +49(0)3834 88 1215
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Lowspeed USB device enumerationg under 5.4.288, but not under 6.8.1
2026-04-02 15:34 Lowspeed USB device enumerationg under 5.4.288, but not under 6.8.1 Fischer, Simon
@ 2026-04-02 16:10 ` Greg KH
2026-04-03 16:34 ` Simon Fischer
` (2 more replies)
2026-05-06 6:58 ` Michal Pecio
1 sibling, 3 replies; 8+ messages in thread
From: Greg KH @ 2026-04-02 16:10 UTC (permalink / raw)
To: Fischer, Simon; +Cc: regressions@lists.linux.dev
On Thu, Apr 02, 2026 at 03:34:35PM +0000, Fischer, Simon wrote:
> Dear list,
>
> I've tried to dig deeper into the issues, tried different quirks and small patches, but was unable to solve this or find the root cause. As this seems to be a regression of 6.8 from 5.4, I hope this is the correct list?
6.8.1 is not supported by anyone but canonical, so there's not much we
can do here, sorry as that is a very old and obsolete kernel missing
tens of thousands of changes.
Can you try running the latest 6.19 release instead?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: Lowspeed USB device enumerationg under 5.4.288, but not under 6.8.1
2026-04-02 16:10 ` Greg KH
@ 2026-04-03 16:34 ` Simon Fischer
2026-04-07 6:33 ` AW: " Fischer, Simon
2026-04-07 7:28 ` Fischer, Simon
2 siblings, 0 replies; 8+ messages in thread
From: Simon Fischer @ 2026-04-03 16:34 UTC (permalink / raw)
To: Greg KH; +Cc: regressions@lists.linux.dev
Hi Greg,
thanks for coming back! I will build and try it, has to wait for after
the easter weekend. Will report back
kind regards
Simon
Am 02.04.2026 um 18:10 schrieb Greg KH:
> On Thu, Apr 02, 2026 at 03:34:35PM +0000, Fischer, Simon wrote:
>> Dear list,
>>
>> I've tried to dig deeper into the issues, tried different quirks and small patches, but was unable to solve this or find the root cause. As this seems to be a regression of 6.8 from 5.4, I hope this is the correct list?
> 6.8.1 is not supported by anyone but canonical, so there's not much we
> can do here, sorry as that is a very old and obsolete kernel missing
> tens of thousands of changes.
>
> Can you try running the latest 6.19 release instead?
>
> thanks,
>
> greg k-h
--
Simon Fischer
Entwickler - CoDaC
Department Operation
Max Planck Institut for Plasmaphysics
Wendelsteinstrasse 1
17491 Greifswald, Germany
Phone: +49(0)3834 88 1215
^ permalink raw reply [flat|nested] 8+ messages in thread
* AW: Lowspeed USB device enumerationg under 5.4.288, but not under 6.8.1
2026-04-02 16:10 ` Greg KH
2026-04-03 16:34 ` Simon Fischer
@ 2026-04-07 6:33 ` Fischer, Simon
2026-04-07 6:49 ` Greg KH
2026-04-07 7:25 ` Thorsten Leemhuis
2026-04-07 7:28 ` Fischer, Simon
2 siblings, 2 replies; 8+ messages in thread
From: Fischer, Simon @ 2026-04-07 6:33 UTC (permalink / raw)
To: Greg KH; +Cc: regressions@lists.linux.dev
Dear Greg, dear all,
the same behaviour is still present with kernel 6.19.11
Anything else I can try/provide?
Thanks
Simon
-----Ursprüngliche Nachricht-----
Von: Greg KH <gregkh@linuxfoundation.org>
Gesendet: Donnerstag, 2. April 2026 18:10
An: Fischer, Simon <simon.fischer@ipp.mpg.de>
Cc: regressions@lists.linux.dev
Betreff: Re: Lowspeed USB device enumerationg under 5.4.288, but not under 6.8.1
On Thu, Apr 02, 2026 at 03:34:35PM +0000, Fischer, Simon wrote:
> Dear list,
>
> I've tried to dig deeper into the issues, tried different quirks and small patches, but was unable to solve this or find the root cause. As this seems to be a regression of 6.8 from 5.4, I hope this is the correct list?
6.8.1 is not supported by anyone but canonical, so there's not much we can do here, sorry as that is a very old and obsolete kernel missing tens of thousands of changes.
Can you try running the latest 6.19 release instead?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: AW: Lowspeed USB device enumerationg under 5.4.288, but not under 6.8.1
2026-04-07 6:33 ` AW: " Fischer, Simon
@ 2026-04-07 6:49 ` Greg KH
2026-04-07 7:25 ` Thorsten Leemhuis
1 sibling, 0 replies; 8+ messages in thread
From: Greg KH @ 2026-04-07 6:49 UTC (permalink / raw)
To: Fischer, Simon; +Cc: regressions@lists.linux.dev
On Tue, Apr 07, 2026 at 06:33:14AM +0000, Fischer, Simon wrote:
> Dear Greg, dear all,
>
> the same behaviour is still present with kernel 6.19.11
>
> Anything else I can try/provide?
I'm sorry, but I have no context here :(
greg k-h
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: AW: Lowspeed USB device enumerationg under 5.4.288, but not under 6.8.1
2026-04-07 6:33 ` AW: " Fischer, Simon
2026-04-07 6:49 ` Greg KH
@ 2026-04-07 7:25 ` Thorsten Leemhuis
1 sibling, 0 replies; 8+ messages in thread
From: Thorsten Leemhuis @ 2026-04-07 7:25 UTC (permalink / raw)
To: Fischer, Simon, Greg KH; +Cc: regressions@lists.linux.dev
On 4/7/26 08:33, Fischer, Simon wrote:
>
> the same behaviour is still present with kernel 6.19.11
> Anything else I can try/provide?
Normally a "git bisection"[1] would be asked for to find the change that
broke things. But given that a 5.4.y versions was the last working
version it might not help much. But if nobody comes up with a better
idea it might be worth a shot.
The 5.4.y kernel you used was also not vanilla, as you mentioned
PREEMPT_RT, which was not upstream back them. Might also be worth ruling
out that it was an influence by trying a 5.4.0 vanilla kernel before
starting a bisection.
[1]
https://docs.kernel.org/admin-guide/verify-bugs-and-bisect-regressions.html
Ciao, Thorsten
> -----Ursprüngliche Nachricht-----
> Von: Greg KH <gregkh@linuxfoundation.org>
> Gesendet: Donnerstag, 2. April 2026 18:10
> An: Fischer, Simon <simon.fischer@ipp.mpg.de>
> Cc: regressions@lists.linux.dev
> Betreff: Re: Lowspeed USB device enumerationg under 5.4.288, but not under 6.8.1
>
> On Thu, Apr 02, 2026 at 03:34:35PM +0000, Fischer, Simon wrote:
>> Dear list,
>>
>> I've tried to dig deeper into the issues, tried different quirks and small patches, but was unable to solve this or find the root cause. As this seems to be a regression of 6.8 from 5.4, I hope this is the correct list?
>
> 6.8.1 is not supported by anyone but canonical, so there's not much we can do here, sorry as that is a very old and obsolete kernel missing tens of thousands of changes.
>
> Can you try running the latest 6.19 release instead?
>
> thanks,
>
> greg k-h
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* AW: Lowspeed USB device enumerationg under 5.4.288, but not under 6.8.1
2026-04-02 16:10 ` Greg KH
2026-04-03 16:34 ` Simon Fischer
2026-04-07 6:33 ` AW: " Fischer, Simon
@ 2026-04-07 7:28 ` Fischer, Simon
2 siblings, 0 replies; 8+ messages in thread
From: Fischer, Simon @ 2026-04-07 7:28 UTC (permalink / raw)
To: Greg KH; +Cc: regressions@lists.linux.dev
On 4/2/26 18:10, Greg KH wrote:
> On Thu, Apr 02, 2026 at 03:34:35PM +0000, Fischer, Simon wrote:
> > Dear list,
> >
> > I've tried to dig deeper into the issues, tried different quirks and small
> patches, but was unable to solve this or find the root cause. As this seems to
> be a regression of 6.8 from 5.4, I hope this is the correct list?
>
> 6.8.1 is not supported by anyone but canonical, so there's not much we
> can do here, sorry as that is a very old and obsolete kernel missing
> tens of thousands of changes.
>
> Can you try running the latest 6.19 release instead?
Sorry, seems me or my outlook messed something up with the correct reply format...
I've tried 6.19.11 now and it shows the same behavior as in my original mail.
Currently building 5.15.202 and 6.0.19 to cross check.
Thanks & bests
Simon
>
> thanks,
>
> greg k-h
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Lowspeed USB device enumerationg under 5.4.288, but not under 6.8.1
2026-04-02 15:34 Lowspeed USB device enumerationg under 5.4.288, but not under 6.8.1 Fischer, Simon
2026-04-02 16:10 ` Greg KH
@ 2026-05-06 6:58 ` Michal Pecio
1 sibling, 0 replies; 8+ messages in thread
From: Michal Pecio @ 2026-05-06 6:58 UTC (permalink / raw)
To: Fischer, Simon; +Cc: regressions@lists.linux.dev
On Thu, 2 Apr 2026 15:34:35 +0000, Fischer, Simon wrote:
> Dear list,
>
> I've tried to dig deeper into the issues, tried different quirks and
> small patches, but was unable to solve this or find the root cause.
> As this seems to be a regression of 6.8 from 5.4, I hope this is the
> correct list?
>
> I got setup with a low speed isochronous USB device (Optec filter
> wheel), that is connected to a Dell R6515 server via a Lindy 300m 2
> Port Fibre Optic USB 3.0 Extender (which enumerates as a chain of
> USB3 super speed hubs). The server is running Ubuntu 24.04 with a
> 6.8.1 RT kernel. When connecting the device, it fails to enumerate:
Hi,
Are you still fighting with this?
I'm afraid I have no better suggestions than others: bisect it.
To avoid bisecting all commits, you could manually bisect major
releases and then test USB commits added by the "bad" release,
as the problem likely came from USB subsystem.
By "low speed", do you mean the 1Mbps data rate defined by USB 1.x?
That's odd, such devices aren't allowed to use isochronous endpoints
so it would be big luck if they work at all with any SW and HW.
Would you mind posting its 'lsusb -v', from the working system?
Your log shows a failure to enumerate some SuperSpeed device, while
any USB1/USB2 device should be showing on another bus (probably 1),
unless your range extender somehow changes "apparent" speed.
Also, if the problem reproduces on current kernels, you could try
sending logs (from a current kernel) to linux-usb in order to reach
more USB developers.
Regards,
Michal
> [ 1843.938804] usb 2-1.2.1: new SuperSpeed USB device number 14 using xhci_hcd
> [ 1843.950893] xhci_hcd 0000:04:00.3: Waiting for status stage event
> [ 1843.950937] xhci_hcd 0000:04:00.3: Waiting for status stage event
> [ 1843.950981] xhci_hcd 0000:04:00.3: Waiting for status stage event
> [ 1843.950998] usb 2-1.2.1: New USB device found, idVendor=0424, idProduct=7016, bcdDevice= 6.26
> [ 1843.951006] usb 2-1.2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
> [ 1843.951013] usb 2-1.2.1: Product: USB7016 Smart Hub
> [ 1843.951018] usb 2-1.2.1: Manufacturer: Microchip
> [ 1843.951365] xhci_hcd 0000:04:00.3: add ep 0x81, slot id 4, new drop flags = 0x0, new add flags = 0x8
> [ 1843.951375] xhci_hcd 0000:04:00.3: xhci_check_bandwidth called for udev 00000000f628da0a
> [ 1843.951387] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1843.952768] xhci_hcd 0000:04:00.3: Successful Endpoint Configure command
> [ 1843.952825] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1843.952865] xhci_hcd 0000:04:00.3: Stopped on No-op or Link TRB for slot 4 ep 2
> [ 1843.952884] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1843.969034] hub 2-1.2.1:1.0: USB hub found
> [ 1843.969108] hub 2-1.2.1:1.0: 3 ports detected
> [ 1843.969459] xhci_hcd 0000:04:00.3: xHCI version 110 needs hub TT think time and number of ports
> [ 1843.969466] xhci_hcd 0000:04:00.3: Set up configure endpoint for hub device.
> [ 1843.969474] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1843.969529] xhci_hcd 0000:04:00.3: Successful Endpoint Configure command
> [ 1844.178598] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1844.178634] xhci_hcd 0000:04:00.3: Slot 5 output ctx = 0x0x0000000179f5f000 (dma)
> [ 1844.178643] xhci_hcd 0000:04:00.3: Slot 5 input ctx = 0x0x00000001311ce000 (dma)
> [ 1844.178652] xhci_hcd 0000:04:00.3: Set slot id 5 dcbaa entry 00000000bb87fc6b to 0x179f5f000
> [ 1844.208850] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.224776] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.240774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.242544] xhci_hcd 0000:04:00.3: Set root hub portnum to 3
> [ 1844.242554] xhci_hcd 0000:04:00.3: Set fake root hub portnum to 1
> [ 1844.242560] xhci_hcd 0000:04:00.3: udev->tt = 0000000000000000
> [ 1844.242565] xhci_hcd 0000:04:00.3: udev->ttport = 0x0
> [ 1844.242573] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1844.250778] usb 2-1.2.1.3: Device not responding to setup address.
> [ 1844.250888] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1844.250919] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1844.250959] xhci_hcd 0000:04:00.3: Slot 5 output ctx = 0x0x0000000179f5f000 (dma)
> [ 1844.250968] xhci_hcd 0000:04:00.3: Slot 5 input ctx = 0x0x00000001311ce000 (dma)
> [ 1844.250976] xhci_hcd 0000:04:00.3: Set slot id 5 dcbaa entry 00000000bb87fc6b to 0x179f5f000
> [ 1844.256773] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.272775] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.288888] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.304774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.320774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.336774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.352774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.368774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.384774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.400774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.416774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.432774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.448774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.458535] xhci_hcd 0000:04:00.3: Set root hub portnum to 3
> [ 1844.458544] xhci_hcd 0000:04:00.3: Set fake root hub portnum to 1
> [ 1844.458550] xhci_hcd 0000:04:00.3: udev->tt = 0000000000000000
> [ 1844.458556] xhci_hcd 0000:04:00.3: udev->ttport = 0x0
> [ 1844.458563] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1844.464774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.466663] usb 2-1.2.1.3: Device not responding to setup address.
> [ 1844.466771] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1844.466801] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1844.466843] xhci_hcd 0000:04:00.3: Slot 5 output ctx = 0x0x0000000179f5f000 (dma)
> [ 1844.466851] xhci_hcd 0000:04:00.3: Slot 5 input ctx = 0x0x00000001311ce000 (dma)
> [ 1844.466860] xhci_hcd 0000:04:00.3: Set slot id 5 dcbaa entry 00000000bb87fc6b to 0x179f5f000
> [ 1844.480774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.496774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.512774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.528774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.544774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.560774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.576774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.592774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.608776] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.624777] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.640774] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.656775] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.672776] xhci_hcd 0000:04:00.3: ep 0x81 - asked for 2 bytes, 1 bytes untransferred
> [ 1844.674524] usb 2-1.2.1.3: device not accepting address 15, error -71
> [ 1844.675151] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1844.675178] xhci_hcd 0000:04:00.3: Bad real port.
> [ 1844.675188] xhci_hcd 0000:04:00.3: // Ding dong!
>
> [this repeats multiple times until giving up]
>
> [ 1864.698065] usb 2-1.2.1.3.4: device not accepting address 25, error -71
> [ 1864.698674] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1864.698711] xhci_hcd 0000:04:00.3: Bad real port.
> [ 1864.698718] usb 2-1.2.1.3-port4: unable to enumerate USB device
> [ 1864.699443] xhci_hcd 0000:04:00.3: Cancel URB 00000000c8fb420b, dev 1.2.1.3, ep 0x81, starting at offset 0x16e8fb050
> [ 1864.699455] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1864.699474] xhci_hcd 0000:04:00.3: Stopped on Transfer TRB for slot 5 ep 2
> [ 1864.699481] xhci_hcd 0000:04:00.3: Removing canceled TD starting at 0x16e8fb050 (dma) in stream 0 URB 00000000c8fb420b
> [ 1864.699489] xhci_hcd 0000:04:00.3: Set TR Deq ptr 0x16e8fb060, cycle 1
>
> [ 1864.699495] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1864.699500] xhci_hcd 0000:04:00.3: xhci_giveback_invalidated_tds: Keep cancelled URB 00000000c8fb420b TD as cancel_status is 2
> [ 1864.699510] xhci_hcd 0000:04:00.3: Successful Set TR Deq Ptr cmd, deq = @16e8fb060
> [ 1864.699517] xhci_hcd 0000:04:00.3: xhci_handle_cmd_set_deq: Giveback cancelled URB 00000000c8fb420b TD
> [ 1864.699522] xhci_hcd 0000:04:00.3: Giveback URB 00000000c8fb420b, len = 0, expected = 2, status = -115
> [ 1864.711179] xhci_hcd 0000:04:00.3: Cancel URB 00000000301149a6, dev 1.2.1, ep 0x81, starting at offset 0x125370300
> [ 1864.711194] xhci_hcd 0000:04:00.3: // Ding dong!
> [ 1864.711211] xhci_hcd 0000:04:00.3: Stopped on Transfer TRB for slot 4 ep 2
> [ 1864.711218] xhci_hcd 0000:04:00.3: Removing canceled TD starting at 0x125370300 (dma) in stream 0 URB 00000000301149a6
> [ 1864.711226] xhci_hcd 0000:04:00.3: Set TR Deq ptr 0x125370310, cycle 1
>
> [ 1864.711232] xhci_hcd 0000:04:00.3: // Ding dong!
>
>
> When booting into a 5.4.288 PREEMPT_RT kernel we were using before
> with, everything works fine (device enumerates and works). When
> exchanging the USB Extender for a Lindy 200m Fibre Optic USB 2.0
> Extender, everything works fine with the 6.8.1 kernel. I cannot
> inject a USB 2.0 hub before the extender, because it is a super speed
> device and not compatible.
>
> Any suggestions how to fix or further investigate the issue would be
> greatly appreciated!
>
> Kind regards
> Simon Fischer
>
>
> Developer
> Department E5 - CoDaC
>
>
> Max Planck Institute for Plasmaphysics
> Wendelsteinstrasse 1
> 17491 Greifswald, Germany
>
> Phone: +49(0)3834 88 1215
>
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2026-05-06 6:58 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-04-02 15:34 Lowspeed USB device enumerationg under 5.4.288, but not under 6.8.1 Fischer, Simon
2026-04-02 16:10 ` Greg KH
2026-04-03 16:34 ` Simon Fischer
2026-04-07 6:33 ` AW: " Fischer, Simon
2026-04-07 6:49 ` Greg KH
2026-04-07 7:25 ` Thorsten Leemhuis
2026-04-07 7:28 ` Fischer, Simon
2026-05-06 6:58 ` Michal Pecio
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