[Bug] pybricksdev waits ~30 seconds after flashing

[BertLindeman]

Describe the bug
Flashing recent firmware, pybricksdev waits on something after "restart ev3.... Done" it takes 30 seconds or a bit more.
After that time pybricksdev ends normally.

To reproduce
Steps to reproduce the behavior:

1. On linux mint with pybricksdev 1.2.0 installed
2. in a terminal enter pybricksdev flash ev3-firmware-build-4054-gitaecbe204.zip or another firware zip
3. See the firmware being installed up to Restarting EV3...Done.
4. Wait for pybricksdev to end >30 seconds.

Expected behavior
pybricksdev to end soon after Restarting EV3...Done.

Screenshots
There is a saying that a picture is worth a 1000 words. Screenshots really help to identify and solve problems.

Extra info
Older firmware does not have the long wait, like
ev3-firmware-build-3989-git44845527.zip.
Maybe related to the latest changes for EV3?

[dlech]

I think this has to do with the USB not resetting after flashing the firmware. I.e. this is the same issue as why USB doesn't work until you turn off the EV3 and turn it back on again.

[BertLindeman]

So harmless and only a bit annoying.
The firmware on the EV3 at that moment is already running happily.

[BertLindeman]

Maybe related.
But might also be related to #2297

sometimes
After flash of NXT with nxt-firmware-build-4058-git85b73404.zip the NXT screen was empty.
The flash command ended nicely without the wait.
I had to restart the NXT by hand to get it running (or to see the normal screen data)

Have done this flash more than 6 times and only 3 times I saw this empty NXT screen with this firmware.
Flashing nxt-firmware-build-4056-git463d45b2_usb.zip* this also occurred, once.

Flash OK, dmesg:

[Sat Jul 26 09:19:08 2025] usb 1-1.2: new full-speed USB device number 123 using ehci-pci
[Sat Jul 26 09:19:08 2025] usb 1-1.2: New USB device found, idVendor=0694, idProduct=0002, bcdDevice= 2.00
[Sat Jul 26 09:19:08 2025] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[Sat Jul 26 09:19:08 2025] usb 1-1.2: Product: NXT + Pybricks
[Sat Jul 26 09:19:08 2025] usb 1-1.2: Manufacturer: LEGO System A/S
[Sat Jul 26 09:20:06 2025] usb 1-1.2: USB disconnect, device number 123

[Sat Jul 26 09:52:57 2025] usb 1-1.2: new full-speed USB device number 124 using ehci-pci
[Sat Jul 26 09:52:57 2025] usb 1-1.2: New USB device found, idVendor=0694, idProduct=0002, bcdDevice= 2.00
[Sat Jul 26 09:52:57 2025] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[Sat Jul 26 09:52:57 2025] usb 1-1.2: Product: NXT + Pybricks
[Sat Jul 26 09:52:57 2025] usb 1-1.2: Manufacturer: LEGO System A/S
[Sat Jul 26 09:53:21 2025] usb 1-1.2: USB disconnect, device number 124

[Sat Jul 26 09:53:29 2025] usb 1-1.2: new full-speed USB device number 125 using ehci-pci
[Sat Jul 26 09:53:29 2025] usb 1-1.2: New USB device found, idVendor=03eb, idProduct=6124, bcdDevice= 1.10
[Sat Jul 26 09:53:29 2025] usb 1-1.2: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[Sat Jul 26 09:53:29 2025] cdc_acm 1-1.2:1.0: ttyACM0: USB ACM device
[Sat Jul 26 09:54:03 2025] usb 1-1.2: USB disconnect, device number 125

[Sat Jul 26 09:54:03 2025] usb 1-1.2: new full-speed USB device number 126 using ehci-pci
[Sat Jul 26 09:54:03 2025] usb 1-1.2: New USB device found, idVendor=0694, idProduct=0002, bcdDevice= 2.00
[Sat Jul 26 09:54:03 2025] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[Sat Jul 26 09:54:03 2025] usb 1-1.2: Product: NXT + Pybricks
[Sat Jul 26 09:54:03 2025] usb 1-1.2: Manufacturer: LEGO System A/S
[Sat Jul 26 09:54:25 2025] usb 1-1.2: USB disconnect, device number 126

Flash ends OK, no 30 seconds wait, but blank NXT screen, dmesg:

[Sat Jul 26 09:54:27 2025] usb 1-1.2: new full-speed USB device number 127 using ehci-pci
[Sat Jul 26 09:54:27 2025] usb 1-1.2: New USB device found, idVendor=0694, idProduct=0002, bcdDevice= 2.00
[Sat Jul 26 09:54:27 2025] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[Sat Jul 26 09:54:27 2025] usb 1-1.2: Product: NXT + Pybricks
[Sat Jul 26 09:54:27 2025] usb 1-1.2: Manufacturer: LEGO System A/S
[Sat Jul 26 09:54:44 2025] usb 1-1.2: USB disconnect, device number 127

[Sat Jul 26 09:54:54 2025] usb 1-1.2: new full-speed USB device number 4 using ehci-pci
[Sat Jul 26 09:54:54 2025] usb 1-1.2: New USB device found, idVendor=03eb, idProduct=6124, bcdDevice= 1.10
[Sat Jul 26 09:54:54 2025] usb 1-1.2: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[Sat Jul 26 09:54:54 2025] cdc_acm 1-1.2:1.0: ttyACM0: USB ACM device
[Sat Jul 26 09:54:59 2025] usb 1-1.2: USB disconnect, device number 4

[Sat Jul 26 09:55:00 2025] usb 1-1.2: new full-speed USB device number 5 using ehci-pci
[Sat Jul 26 09:55:05 2025] usb 1-1.2: unable to get BOS descriptor or descriptor too short
[Sat Jul 26 09:55:15 2025] usb 1-1.2: unable to read config index 0 descriptor/start: -110
[Sat Jul 26 09:55:15 2025] usb 1-1.2: can't read configurations, error -110
[Sat Jul 26 09:55:15 2025] usb 1-1.2: new full-speed USB device number 6 using ehci-pci
[Sat Jul 26 09:55:31 2025] usb 1-1.2: device descriptor read/64, error -110
[Sat Jul 26 09:55:47 2025] usb 1-1.2: device descriptor read/64, error -110
[Sat Jul 26 09:55:47 2025] usb 1-1-port2: attempt power cycle
[Sat Jul 26 09:55:47 2025] usb 1-1.2: new full-speed USB device number 7 using ehci-pci
[Sat Jul 26 09:55:59 2025] usb 1-1.2: device not accepting address 7, error -110
[Sat Jul 26 09:55:59 2025] usb 1-1.2: new full-speed USB device number 8 using ehci-pci
[Sat Jul 26 09:56:10 2025] usb 1-1.2: device not accepting address 8, error -110
[Sat Jul 26 09:56:10 2025] usb 1-1-port2: unable to enumerate USB device
[Sat Jul 26 09:56:34 2025] usb 1-1.2: new full-speed USB device number 9 using ehci-pci
[Sat Jul 26 09:56:49 2025] usb 1-1.2: device descriptor read/64, error -110
[Sat Jul 26 09:57:05 2025] usb 1-1.2: device descriptor read/64, error -110
[Sat Jul 26 09:57:05 2025] usb 1-1.2: new full-speed USB device number 10 using ehci-pci
[Sat Jul 26 09:57:21 2025] usb 1-1.2: device descriptor read/64, error -110

[dlech]

After flash of NXT

NXT and EV3 have completely different USB controllers, so all bugs with NXT USB should be reported separate from EV3 USB.

[BertLindeman]

After flash of NXT

NXT and EV3 have completely different USB controllers, so all bugs with NXT USB should be reported separate from EV3 USB.

Will report the NXT separately if it still occurs after the latest USB update.