On Thu, 25 Oct 2012, Stefan May wrote: > Dear USB-Developers, > > I am having a strange Problem on Ubuntu Linux (11.10 and 12.04) using a > thermal camera (Cypress FX2 chip) in isochronous mode. The transmission > of data breaks with the error code -EPROTO. The curious thing is, that > it runs very well on the same distribution, when it is a VMWare guest > system. That means: > - Native Ubuntu Linux: Frequently USB isochronous frame lost (-71) > - Ubuntu Linux as VMWare guest on a Ubuntu Host!: No errors! > > I changed cables, switched USB ports, added quirks ... no effect. > > Below, I've attached traces from usbmon. Could someone give me a hint > what is going wrong there? Do you know with parameters have to be > respected on the firmware side? Below, I've attached lsusb output too. For the second usbmon trace, did you collect the usbmon data from within the guest or within the host? It's quite possible that VMWare is changing the error codes to 0s. You could try collecting usbmon traces in both the host and the guest simultaneously, for comparison. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
