VB 4.2.12 - keyboard and ascii barcode scanner inconsistencies

[error_401]

Opening this bug in version 4.2.12 in reference to:

Ticket #11671

in version 4.1.18

Using the new version the same bug occurs altering the input from the scanner in the guest OS. The host scans correctly all the time, in the guest it drops parts of the ASCII character scan.

[error_401]

Tested again in version 4.2.16 (although still running guest additions 4.2.14) Same USB barcode scanner.

Same behaviour with a Linux guest in a Linux host VBox 4.2.16

Host OS: Debian 7.0 Wheezy Guest OS: Debian 6.0 Squeeze Guest OS: Windows XP SP3

it still drops characters in the guest while scanning into the host is flawless.

[Klaus Espenlaub]

You forgot to mention how the input of the barcode scanner reaches the VM - does this go through the VirtualBox keyboard emulation, or are you using USB passthrough?

Either way, it looks like the virtualization adds just enough overhead that the super fast input signalling by the barcode scanner triggers keyboard buffer overruns...

[error_401]

The input goes directly via USB passthroug.

Connected Keyboard to USB1 and scanner to USB2

[error_401]

New release - new test

Still exactly the same. In the client it drops characters all once in a while. It still renders the client useless for me as correct input from the barcode scanner is crucial.

Is there a way to narrow down the problem. If somebody tells me how to set up debugging or logging I may try that.

dmesg on the host shows that the barcode scanner has properly been identified and added as USB input device. No problems at all in the host. Only the clients (be it WIN XP or Debian 6) drop characters.

[Klaus Espenlaub]

If USB passthrough loses keys then the device is sending them super fast, tripping over the somewhat unpredictable delay of delivering URBs to the VM. The host has a lot simpler task, adding scheduling uncertainty, VirtualBox and the guest OS will not improve this.

Would still be great to get VBox.log to know more about the runtime properties of your VM.

[error_401]

I have checked this issue again with the very same results and problems. Attached two files. One ist the VBox.log after having tested and shut down the client. One is the tail of the linux dmesg file which shows how the barcode scanner was detected. Hope this helps with troubleshooting.

[aeichner]

Please reopen if still relevant with a recent VirtualBox release.