Continuous flashing of the same device freezes the flashing at some point on Linux

[VeliMattiLahtela]

The following issue has been seen with newest raspbian and Ubuntu 14.04 LTS:

The binary file size is around 900Kb.

The board K64F:
Version: 0226
Build: Aug 24 2015 17:06:30
Git Commit SHA: 27a236b9fe39c674a703c5c89655fbd26b8e27e1
Git Local mods: Yes

Running a bash script that repeats the same flashing command will at some point "freeze" the flashing.
The script I'm running:

#!/bin/bash
for i in `seq 1 10`;
do
   sudo pyocd-flashtool -d debug -b 02400226c36f3e5b0000000000000000000000003eb6c3e3 my_bin.bin
done   

I have not determined an exact amount of flashing times required before it freezes, seems to be quite random.

This is not reproducible on Windows.

I also noticed that adding "sudo pyocd-tool -b 02400226c36f3e5b0000000000000000000000003eb6c3e3 reset" before the flash command prevents the freeze.

Running the flash with debug doesn't provide any more information when the "freeze" happens.

I tried to backtrace the fail with no luck.

[c1728p9]

That is very strange. Are you running Ubuntu inside a virtual machine or natively? Also, you are unable to get the python backtrace when this happens?

[VeliMattiLahtela]

Ubuntu was run on VM.

[c1728p9]

Was this inside virtual box? It has some known USB driver bugs. There was a PR to work around this a while back, but it never got merged:
#154

[VeliMattiLahtela]

Not with Virtual box, VMware Player was used.

[c1728p9]

If it is the same issue as #154 this should be fixed by the timeout added here. If you are still seeing this hang please re-open with steps to reproduce.