(cache)How come a USB device is sometimes not recognized without re-plugging the USB-OTG adapter?

exerceo · 10-09-2025, 04:41 PM

A newly inserted USB device is sometimes not recognized without re-plugging USB-OTG adapter.

When unplugging a USB stick from the USB-OTG adapter and inserting a new one, the new USB stick is not detected.

When unplugging the USB-OTG adapter from the laptop and inserting it again, the new USB stick is recognized.

Is this normal? Has someone else had this experience? Has anyone had a similar experience? And how to detect the new device without physically unplugging the USB-OTG adapter?

For clarity:

Code:

USB flash drive
|   USB-A - plugging in new device = new device not detected.
|   |             USB-OTG - re-plugging = new device detected.
|   |             |  
|   |             | __________
↓   ↓             ↓ | Laptop  |
==- >|||)---------=-|_________|
                   ↑
                   USB-C ending

dmesg:

Code:

[2502221.569255] usb 4-1: USB disconnect, device number 2
[2502221.612368] sd 5:0:0:0: [sdd] Synchronizing SCSI cache
[2502221.612474] sd 5:0:0:0: [sdd] Synchronize Cache(10) failed: Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK

No new dmesg appear when plugging the new device.

frankbell · 10-09-2025, 08:38 PM

I have encountered this occasionally. I've always thought the device just didn't make a good connection the first time.

onebuck · 10-10-2025, 09:04 AM

Hi,
Apparently your On-The-Go adapter had lost it's connection/system control and when you removed device then it was identified again thus the USB plugged in was identified. I would think your OTG device could be at fault or the USB port connections are not stable. But when re-insertion a new connection was established by the system.

MargueriteBScarlett · 11-10-2025, 08:20 AM

Thank you for sharing

TB0ne · 11-10-2025, 09:18 AM

Quote:

Originally Posted by MargueriteBScarlett

Thank you for sharing

What helped you most in this thread???

::EDIT::
Spammer reported.

ArthurSeta · 11-10-2025, 09:48 AM

It happens when the OTG adapter doesn’t fully renegotiate power and data roles after the first disconnect, so the host never sees a new device event. Re-initializing the adapter forces a new handshake; replacing the OTG cable or using a powered hub usually fixes the detection issue.

TB0ne · 11-10-2025, 10:19 AM

Quote:

Originally Posted by ArthurSeta

It happens when the OTG adapter doesn’t fully renegotiate power and data roles after the first disconnect, so the host never sees a new device event. Re-initializing the adapter forces a new handshake; replacing the OTG cable or using a powered hub usually fixes the detection issue.

Right, that's what the OP was told and did. Did you read the thread?

TB0ne · 11-15-2025, 03:33 PM

Spammer reported