Hi Hans, I about to dive into this issue. I have not yet read libusbx code but
I can basically assure you this errno=14 can be caused by USB transfer errors.
Here is the evidence:
We develop a USB-based ultrasound hardware here at the university and the USB
transfer errors are our long time friends...
If I just communicate with our hardware without turning the high-voltage power
source, the communication runs flawless for days. When I turn the HV power then
a lot of EMI noise starts being generated (to the point that a scope with
grounded tip can actually capture and show the ultrasound excitation just by
inductance - i just need to bring the tip somewhat close to the circuit).
This level of noise causes a lot of trouble to USB host controllers. Some PC's
chipsets may freeze requiring power off. However, using Raspberry PI USB host +
libusbx it seems that it is possible to recover this condition by software: by
killing my client and then restarting it I'm able to reopen the USB device just
fine.
So, in short, i'm about to move the hardware to my office so it will be easy to
reproduce this condition. Then I hope we will be able to fix it properly.
---
Reply to this email directly or view it on GitHub:
https://github.com/libusbx/libusbx/issues/76#issuecomment-31648004
------------------------------------------------------------------------------
Rapidly troubleshoot problems before they affect your business. Most IT
organizations don't have a clear picture of how application performance
affects their revenue. With AppDynamics, you get 100% visibility into your
Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro!
http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk
_______________________________________________
libusbx-devel mailing list
libusbx-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/libusbx-devel
