* usb port enumeration changed?
@ 2021-07-27 1:15 Eyal Lebedinsky
2021-07-27 2:23 ` Alan Stern
0 siblings, 1 reply; 4+ messages in thread
From: Eyal Lebedinsky @ 2021-07-27 1:15 UTC (permalink / raw)
To: list linux-usb
I know that device numbers change, but bus/port numbers are stable and reflect the physical layout
of the hubs and devices. I relied for years on these port numbers to identify specific (otherwise
identical) devices.
Searching the list (I am now subscribed) and the web did not yield an answer.
For example, I have two TEMPer temperature sensor devices attached. They are both plugged into
a 4-port USB3 hub. They are on ports 3 and 4. Port 2 is unused and port 1 has a bluetooth radio
attached. I also have 5 dvb usb tuners which stayed in their old positions.
Until now (fedora 34, last on 5.12.17-300.fc34.x86_64), I would see this:
$ lsusb
Bus 001 Device 013: ID 0c45:7401 Microdia TEMPer Temperature Sensor
Bus 001 Device 025: ID 0c45:7401 Microdia TEMPer Temperature Sensor
$ lsusb -t
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/10p, 10000M
|__ Port 4: Dev 2, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 4: Dev 4, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 5: Dev 3, If 0, Class=Hub, Driver=hub/4p, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M
|__ Port 2: Dev 26, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 2: Dev 27, If 1, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 2: Dev 27, If 0, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 4: Dev 3, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 3: Dev 10, If 1, Class=Vendor Specific Class, Driver=, 480M
|__ Port 3: Dev 10, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
|__ Port 1: Dev 6, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
|__ Port 1: Dev 6, If 1, Class=Vendor Specific Class, Driver=, 480M
|__ Port 4: Dev 12, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 3: Dev 15, If 0, Class=Printer, Driver=usblp, 12M
|__ Port 1: Dev 14, If 1, Class=Vendor Specific Class, Driver=, 480M
|__ Port 1: Dev 14, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
|__ Port 4: Dev 16, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
|__ Port 4: Dev 16, If 1, Class=Vendor Specific Class, Driver=, 480M
|__ Port 2: Dev 8, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
|__ Port 2: Dev 8, If 1, Class=Vendor Specific Class, Driver=, 480M
|__ Port 5: Dev 5, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 1: Dev 20, If 0, Class=Wireless, Driver=btusb, 12M
|__ Port 1: Dev 20, If 1, Class=Wireless, Driver=btusb, 12M
|__ Port 3: Dev 25, If 0, Class=Human Interface Device, Driver=, 1.5M <<<<<
|__ Port 3: Dev 25, If 1, Class=Human Interface Device, Driver=, 1.5M <<<<<
|__ Port 4: Dev 13, If 0, Class=Human Interface Device, Driver=, 1.5M <<<<<
|__ Port 4: Dev 13, If 1, Class=Human Interface Device, Driver=, 1.5M <<<<<
|__ Port 6: Dev 19, If 0, Class=Human Interface Device, Driver=usbfs, 1.5M
The TEMPer devices show on Bus 01 as was always:
Port 5.Port 3 (Dev 11)
Port 5.Port 4 (Dev 13)
After rebooting the newly installed kernel 5.13.4-200.fc34.x86_64 I get:
$ lsusb
Bus 001 Device 012: ID 0c45:7401 Microdia TEMPer Temperature Sensor
Bus 001 Device 003: ID 0c45:7401 Microdia TEMPer Temperature Sensor
$ lsusb -t
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/10p, 10000M
|__ Port 4: Dev 2, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 4: Dev 4, If 0, Class=Hub, Driver=hub/4p, 5000M
|__ Port 5: Dev 3, If 0, Class=Hub, Driver=hub/4p, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M
|__ Port 2: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 2: Dev 4, If 1, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 2: Dev 4, If 0, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 3: Dev 3, If 0, Class=Human Interface Device, Driver=, 1.5M <<<<<
|__ Port 3: Dev 3, If 1, Class=Human Interface Device, Driver=, 1.5M <<<<<
|__ Port 4: Dev 5, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 3: Dev 11, If 1, Class=Vendor Specific Class, Driver=, 480M
|__ Port 3: Dev 11, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
|__ Port 1: Dev 7, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
|__ Port 1: Dev 7, If 1, Class=Vendor Specific Class, Driver=, 480M
|__ Port 4: Dev 13, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 3: Dev 15, If 0, Class=Printer, Driver=usblp, 12M
|__ Port 1: Dev 14, If 1, Class=Vendor Specific Class, Driver=, 480M
|__ Port 1: Dev 14, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
|__ Port 4: Dev 16, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
|__ Port 4: Dev 16, If 1, Class=Vendor Specific Class, Driver=, 480M
|__ Port 2: Dev 9, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
|__ Port 2: Dev 9, If 1, Class=Vendor Specific Class, Driver=, 480M
|__ Port 5: Dev 6, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 1: Dev 10, If 0, Class=Wireless, Driver=btusb, 12M
|__ Port 1: Dev 10, If 1, Class=Wireless, Driver=btusb, 12M
|__ Port 3: Dev 12, If 0, Class=Human Interface Device, Driver=, 1.5M <<<<<
|__ Port 3: Dev 12, If 1, Class=Human Interface Device, Driver=, 1.5M <<<<<
|__ Port 6: Dev 18, If 0, Class=Human Interface Device, Driver=usbfs, 1.5M
One can see that the TEMPer devices are now showing on Bus 01 but in separate positions:
Port 3 (Dev 3) new position
Port 5.Port 3 (Dev 12) old position
This, naturally, confuses my script that collects the data from these sensors (I use temper-poll).
Is this an intentional change?
If so then what is the way to stably disambiguate usb devices (there is no s/n available)?
If no change was expected then does this reflect a possible hwr problem here?
--
Eyal Lebedinsky (eyal@eyal.emu.id.au)
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: usb port enumeration changed?
2021-07-27 1:15 usb port enumeration changed? Eyal Lebedinsky
@ 2021-07-27 2:23 ` Alan Stern
2021-07-27 6:43 ` usb port enumeration changed? [resolved] Eyal Lebedinsky
0 siblings, 1 reply; 4+ messages in thread
From: Alan Stern @ 2021-07-27 2:23 UTC (permalink / raw)
To: Eyal Lebedinsky; +Cc: list linux-usb
On Tue, Jul 27, 2021 at 11:15:11AM +1000, Eyal Lebedinsky wrote:
> I know that device numbers change, but bus/port numbers are stable and reflect the physical layout
> of the hubs and devices. I relied for years on these port numbers to identify specific (otherwise
> identical) devices.
Port numbers are stable. Bus numbers aren't. (They do tend to be stable
but there are no guarantees.)
> Searching the list (I am now subscribed) and the web did not yield an answer.
>
> For example, I have two TEMPer temperature sensor devices attached. They are both plugged into
> a 4-port USB3 hub. They are on ports 3 and 4. Port 2 is unused and port 1 has a bluetooth radio
> attached. I also have 5 dvb usb tuners which stayed in their old positions.
>
> Until now (fedora 34, last on 5.12.17-300.fc34.x86_64), I would see this:
>
> $ lsusb
> Bus 001 Device 013: ID 0c45:7401 Microdia TEMPer Temperature Sensor
> Bus 001 Device 025: ID 0c45:7401 Microdia TEMPer Temperature Sensor
>
> $ lsusb -t
> /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/10p, 10000M
> |__ Port 4: Dev 2, If 0, Class=Hub, Driver=hub/4p, 5000M
> |__ Port 4: Dev 4, If 0, Class=Hub, Driver=hub/4p, 5000M
> |__ Port 5: Dev 3, If 0, Class=Hub, Driver=hub/4p, 5000M
> /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M
> |__ Port 2: Dev 26, If 0, Class=Hub, Driver=hub/4p, 480M
> |__ Port 2: Dev 27, If 1, Class=Human Interface Device, Driver=usbhid, 12M
> |__ Port 2: Dev 27, If 0, Class=Human Interface Device, Driver=usbhid, 12M
> |__ Port 4: Dev 3, If 0, Class=Hub, Driver=hub/4p, 480M
> |__ Port 3: Dev 10, If 1, Class=Vendor Specific Class, Driver=, 480M
> |__ Port 3: Dev 10, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
> |__ Port 1: Dev 6, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
> |__ Port 1: Dev 6, If 1, Class=Vendor Specific Class, Driver=, 480M
> |__ Port 4: Dev 12, If 0, Class=Hub, Driver=hub/4p, 480M
> |__ Port 3: Dev 15, If 0, Class=Printer, Driver=usblp, 12M
> |__ Port 1: Dev 14, If 1, Class=Vendor Specific Class, Driver=, 480M
> |__ Port 1: Dev 14, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
> |__ Port 4: Dev 16, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
> |__ Port 4: Dev 16, If 1, Class=Vendor Specific Class, Driver=, 480M
> |__ Port 2: Dev 8, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
> |__ Port 2: Dev 8, If 1, Class=Vendor Specific Class, Driver=, 480M
> |__ Port 5: Dev 5, If 0, Class=Hub, Driver=hub/4p, 480M
> |__ Port 1: Dev 20, If 0, Class=Wireless, Driver=btusb, 12M
> |__ Port 1: Dev 20, If 1, Class=Wireless, Driver=btusb, 12M
> |__ Port 3: Dev 25, If 0, Class=Human Interface Device, Driver=, 1.5M <<<<<
> |__ Port 3: Dev 25, If 1, Class=Human Interface Device, Driver=, 1.5M <<<<<
> |__ Port 4: Dev 13, If 0, Class=Human Interface Device, Driver=, 1.5M <<<<<
> |__ Port 4: Dev 13, If 1, Class=Human Interface Device, Driver=, 1.5M <<<<<
> |__ Port 6: Dev 19, If 0, Class=Human Interface Device, Driver=usbfs, 1.5M
>
> The TEMPer devices show on Bus 01 as was always:
> Port 5.Port 3 (Dev 11)
In fact it is device 25; see above. There is o device 11 in the lsusb
output.
> Port 5.Port 4 (Dev 13)
>
> After rebooting the newly installed kernel 5.13.4-200.fc34.x86_64 I get:
>
> $ lsusb
> Bus 001 Device 012: ID 0c45:7401 Microdia TEMPer Temperature Sensor
> Bus 001 Device 003: ID 0c45:7401 Microdia TEMPer Temperature Sensor
>
> $ lsusb -t
> /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/10p, 10000M
> |__ Port 4: Dev 2, If 0, Class=Hub, Driver=hub/4p, 5000M
> |__ Port 4: Dev 4, If 0, Class=Hub, Driver=hub/4p, 5000M
> |__ Port 5: Dev 3, If 0, Class=Hub, Driver=hub/4p, 5000M
> /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M
> |__ Port 2: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
> |__ Port 2: Dev 4, If 1, Class=Human Interface Device, Driver=usbhid, 12M
> |__ Port 2: Dev 4, If 0, Class=Human Interface Device, Driver=usbhid, 12M
> |__ Port 3: Dev 3, If 0, Class=Human Interface Device, Driver=, 1.5M <<<<<
> |__ Port 3: Dev 3, If 1, Class=Human Interface Device, Driver=, 1.5M <<<<<
> |__ Port 4: Dev 5, If 0, Class=Hub, Driver=hub/4p, 480M
> |__ Port 3: Dev 11, If 1, Class=Vendor Specific Class, Driver=, 480M
> |__ Port 3: Dev 11, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
> |__ Port 1: Dev 7, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
> |__ Port 1: Dev 7, If 1, Class=Vendor Specific Class, Driver=, 480M
> |__ Port 4: Dev 13, If 0, Class=Hub, Driver=hub/4p, 480M
> |__ Port 3: Dev 15, If 0, Class=Printer, Driver=usblp, 12M
> |__ Port 1: Dev 14, If 1, Class=Vendor Specific Class, Driver=, 480M
> |__ Port 1: Dev 14, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
> |__ Port 4: Dev 16, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
> |__ Port 4: Dev 16, If 1, Class=Vendor Specific Class, Driver=, 480M
> |__ Port 2: Dev 9, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
> |__ Port 2: Dev 9, If 1, Class=Vendor Specific Class, Driver=, 480M
> |__ Port 5: Dev 6, If 0, Class=Hub, Driver=hub/4p, 480M
> |__ Port 1: Dev 10, If 0, Class=Wireless, Driver=btusb, 12M
> |__ Port 1: Dev 10, If 1, Class=Wireless, Driver=btusb, 12M
> |__ Port 3: Dev 12, If 0, Class=Human Interface Device, Driver=, 1.5M <<<<<
> |__ Port 3: Dev 12, If 1, Class=Human Interface Device, Driver=, 1.5M <<<<<
> |__ Port 6: Dev 18, If 0, Class=Human Interface Device, Driver=usbfs, 1.5M
>
> One can see that the TEMPer devices are now showing on Bus 01 but in separate positions:
> Port 3 (Dev 3) new position
> Port 5.Port 3 (Dev 12) old position
Are you certain that device 3 really is one of the TEMPer devices and not
something else?
> This, naturally, confuses my script that collects the data from these sensors (I use temper-poll).
Are you certain you didn't change the wiring? I can't think of any other
explanation.
> Is this an intentional change?
Nope.
> If so then what is the way to stably disambiguate usb devices (there is no s/n available)?
Using port paths is a fairly good way to go. Unless the devices get
unplugged and then plugged back into different ports.
> If no change was expected then does this reflect a possible hwr problem here?
No, it represents a physical impossibility. Consider the following thought
experiment: You unplug the four-port hub that is device 6 on bus 1 (port
5). That will of course also disconnect anything that is plugged into that
hub, presumably including your two temperature sensors. But if one of them
is plugged into port 3 of the root hub instead, it won't be affected by
this operation. So what really happens?
Alan Stern
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: usb port enumeration changed? [resolved]
2021-07-27 2:23 ` Alan Stern
@ 2021-07-27 6:43 ` Eyal Lebedinsky
2021-07-27 13:39 ` Alan Stern
0 siblings, 1 reply; 4+ messages in thread
From: Eyal Lebedinsky @ 2021-07-27 6:43 UTC (permalink / raw)
To: list linux-usb
See end of message.
On 27/07/2021 12.23, Alan Stern wrote:
> On Tue, Jul 27, 2021 at 11:15:11AM +1000, Eyal Lebedinsky wrote:
>> I know that device numbers change, but bus/port numbers are stable and reflect the physical layout
>> of the hubs and devices. I relied for years on these port numbers to identify specific (otherwise
>> identical) devices.
>
> Port numbers are stable. Bus numbers aren't. (They do tend to be stable
> but there are no guarantees.)
>
>> Searching the list (I am now subscribed) and the web did not yield an answer.
>>
>> For example, I have two TEMPer temperature sensor devices attached. They are both plugged into
>> a 4-port USB3 hub. They are on ports 3 and 4. Port 2 is unused and port 1 has a bluetooth radio
>> attached. I also have 5 dvb usb tuners which stayed in their old positions.
>>
>> Until now (fedora 34, last on 5.12.17-300.fc34.x86_64), I would see this:
>>
>> $ lsusb
>> Bus 001 Device 013: ID 0c45:7401 Microdia TEMPer Temperature Sensor
>> Bus 001 Device 025: ID 0c45:7401 Microdia TEMPer Temperature Sensor
>>
>> $ lsusb -t
>> /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/10p, 10000M
>> |__ Port 4: Dev 2, If 0, Class=Hub, Driver=hub/4p, 5000M
>> |__ Port 4: Dev 4, If 0, Class=Hub, Driver=hub/4p, 5000M
>> |__ Port 5: Dev 3, If 0, Class=Hub, Driver=hub/4p, 5000M
>> /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M
>> |__ Port 2: Dev 26, If 0, Class=Hub, Driver=hub/4p, 480M
>> |__ Port 2: Dev 27, If 1, Class=Human Interface Device, Driver=usbhid, 12M
>> |__ Port 2: Dev 27, If 0, Class=Human Interface Device, Driver=usbhid, 12M
>> |__ Port 4: Dev 3, If 0, Class=Hub, Driver=hub/4p, 480M
>> |__ Port 3: Dev 10, If 1, Class=Vendor Specific Class, Driver=, 480M
>> |__ Port 3: Dev 10, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
>> |__ Port 1: Dev 6, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
>> |__ Port 1: Dev 6, If 1, Class=Vendor Specific Class, Driver=, 480M
>> |__ Port 4: Dev 12, If 0, Class=Hub, Driver=hub/4p, 480M
>> |__ Port 3: Dev 15, If 0, Class=Printer, Driver=usblp, 12M
>> |__ Port 1: Dev 14, If 1, Class=Vendor Specific Class, Driver=, 480M
>> |__ Port 1: Dev 14, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
>> |__ Port 4: Dev 16, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
>> |__ Port 4: Dev 16, If 1, Class=Vendor Specific Class, Driver=, 480M
>> |__ Port 2: Dev 8, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
>> |__ Port 2: Dev 8, If 1, Class=Vendor Specific Class, Driver=, 480M
>> |__ Port 5: Dev 5, If 0, Class=Hub, Driver=hub/4p, 480M
>> |__ Port 1: Dev 20, If 0, Class=Wireless, Driver=btusb, 12M
>> |__ Port 1: Dev 20, If 1, Class=Wireless, Driver=btusb, 12M
>> |__ Port 3: Dev 25, If 0, Class=Human Interface Device, Driver=, 1.5M <<<<<
>> |__ Port 3: Dev 25, If 1, Class=Human Interface Device, Driver=, 1.5M <<<<<
>> |__ Port 4: Dev 13, If 0, Class=Human Interface Device, Driver=, 1.5M <<<<<
>> |__ Port 4: Dev 13, If 1, Class=Human Interface Device, Driver=, 1.5M <<<<<
>> |__ Port 6: Dev 19, If 0, Class=Human Interface Device, Driver=usbfs, 1.5M
>>
>> The TEMPer devices show on Bus 01 as was always:
>> Port 5.Port 3 (Dev 11)
>
> In fact it is device 25; see above. There is o device 11 in the lsusb
> output.
>
>> Port 5.Port 4 (Dev 13)
>>
>> After rebooting the newly installed kernel 5.13.4-200.fc34.x86_64 I get:
>>
>> $ lsusb
>> Bus 001 Device 012: ID 0c45:7401 Microdia TEMPer Temperature Sensor
>> Bus 001 Device 003: ID 0c45:7401 Microdia TEMPer Temperature Sensor
>>
>> $ lsusb -t
>> /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/10p, 10000M
>> |__ Port 4: Dev 2, If 0, Class=Hub, Driver=hub/4p, 5000M
>> |__ Port 4: Dev 4, If 0, Class=Hub, Driver=hub/4p, 5000M
>> |__ Port 5: Dev 3, If 0, Class=Hub, Driver=hub/4p, 5000M
>> /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M
>> |__ Port 2: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
>> |__ Port 2: Dev 4, If 1, Class=Human Interface Device, Driver=usbhid, 12M
>> |__ Port 2: Dev 4, If 0, Class=Human Interface Device, Driver=usbhid, 12M
>> |__ Port 3: Dev 3, If 0, Class=Human Interface Device, Driver=, 1.5M <<<<<
>> |__ Port 3: Dev 3, If 1, Class=Human Interface Device, Driver=, 1.5M <<<<<
>> |__ Port 4: Dev 5, If 0, Class=Hub, Driver=hub/4p, 480M
>> |__ Port 3: Dev 11, If 1, Class=Vendor Specific Class, Driver=, 480M
>> |__ Port 3: Dev 11, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
>> |__ Port 1: Dev 7, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
>> |__ Port 1: Dev 7, If 1, Class=Vendor Specific Class, Driver=, 480M
>> |__ Port 4: Dev 13, If 0, Class=Hub, Driver=hub/4p, 480M
>> |__ Port 3: Dev 15, If 0, Class=Printer, Driver=usblp, 12M
>> |__ Port 1: Dev 14, If 1, Class=Vendor Specific Class, Driver=, 480M
>> |__ Port 1: Dev 14, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
>> |__ Port 4: Dev 16, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
>> |__ Port 4: Dev 16, If 1, Class=Vendor Specific Class, Driver=, 480M
>> |__ Port 2: Dev 9, If 0, Class=Vendor Specific Class, Driver=dvb_usb_rtl28xxu, 480M
>> |__ Port 2: Dev 9, If 1, Class=Vendor Specific Class, Driver=, 480M
>> |__ Port 5: Dev 6, If 0, Class=Hub, Driver=hub/4p, 480M
>> |__ Port 1: Dev 10, If 0, Class=Wireless, Driver=btusb, 12M
>> |__ Port 1: Dev 10, If 1, Class=Wireless, Driver=btusb, 12M
>> |__ Port 3: Dev 12, If 0, Class=Human Interface Device, Driver=, 1.5M <<<<<
>> |__ Port 3: Dev 12, If 1, Class=Human Interface Device, Driver=, 1.5M <<<<<
>> |__ Port 6: Dev 18, If 0, Class=Human Interface Device, Driver=usbfs, 1.5M
>>
>> One can see that the TEMPer devices are now showing on Bus 01 but in separate positions:
>> Port 3 (Dev 3) new position
>> Port 5.Port 3 (Dev 12) old position
>
> Are you certain that device 3 really is one of the TEMPer devices and not
> something else?
>
>> This, naturally, confuses my script that collects the data from these sensors (I use temper-poll).
>
> Are you certain you didn't change the wiring? I can't think of any other
> explanation.
>
>> Is this an intentional change?
>
> Nope.
>
>> If so then what is the way to stably disambiguate usb devices (there is no s/n available)?
>
> Using port paths is a fairly good way to go. Unless the devices get
> unplugged and then plugged back into different ports.
>
>> If no change was expected then does this reflect a possible hwr problem here?
>
> No, it represents a physical impossibility. Consider the following thought
> experiment: You unplug the four-port hub that is device 6 on bus 1 (port
> 5). That will of course also disconnect anything that is plugged into that
> hub, presumably including your two temperature sensors. But if one of them
> is plugged into port 3 of the root hub instead, it won't be affected by
> this operation. So what really happens?
Seeing the confidence of the reply I decided to do more testing.
- booting the old kernel did not fix it.
- unplugging and re-plugging the devices did not help.
I then crawled under the table and followed the large cables bundle to find that I should have
trusted my instruments (the USB system).
While the correct cable was plugged into the correct socket, the far end used an extension which
*was* plugged into the wrong thing. I then remembered that at one time the cable was pulled off
accidentally and quickly re-attached...
In short, I am stupid and apology for the noise.
> Alan Stern
Regards,
--
Eyal Lebedinsky (eyal@eyal.emu.id.au)
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: usb port enumeration changed? [resolved]
2021-07-27 6:43 ` usb port enumeration changed? [resolved] Eyal Lebedinsky
@ 2021-07-27 13:39 ` Alan Stern
0 siblings, 0 replies; 4+ messages in thread
From: Alan Stern @ 2021-07-27 13:39 UTC (permalink / raw)
To: Eyal Lebedinsky; +Cc: list linux-usb
On Tue, Jul 27, 2021 at 04:43:35PM +1000, Eyal Lebedinsky wrote:
> Seeing the confidence of the reply I decided to do more testing.
> - booting the old kernel did not fix it.
> - unplugging and re-plugging the devices did not help.
>
> I then crawled under the table and followed the large cables bundle to find that I should have
> trusted my instruments (the USB system).
>
> While the correct cable was plugged into the correct socket, the far end used an extension which
> *was* plugged into the wrong thing. I then remembered that at one time the cable was pulled off
> accidentally and quickly re-attached...
>
> In short, I am stupid and apology for the noise.
It happens to the best of us. Don't worry about it. ;-)
Alan Stern
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-07-27 13:39 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-27 1:15 usb port enumeration changed? Eyal Lebedinsky
2021-07-27 2:23 ` Alan Stern
2021-07-27 6:43 ` usb port enumeration changed? [resolved] Eyal Lebedinsky
2021-07-27 13:39 ` Alan Stern
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