On Feb 27, 2011, at 5:43 PM, Alan Stern wrote: > Please have your email client wrap lines after 72 columns or so. Ah, OK. I had assumed vger would do that for me :-/ > <snip> > You can learn a lot by looking at a usbmon trace. See > Documentation/usb/usbmon.txt. Perfect! The timestamp and datalen will answer my current questions. > > Extreme inefficiencies like this are almost always the device's fault. I'm certainly suspecting that now. I put some lame instrumentation tweaks into the cdc-acm driver, and aside from destabilizing the driver, it makes me think the device is sending short transfers. I assume that leads to outrageous amounts of buffer churning. -dave > > 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
