Hi, Why high-bandwidth USB 1.1 isochronous devices don't work on 2.0 hosts?
I have an ADSL modem of this kind which I would like to use on a companion-less 2.0 host in my router, but I can't because it fails with ENOSPC errors. Same thing happens on my PC when connected through a 2.0 hub, but it works perfectly on 1.1 and 3.0 hosts, with or without hubs. This seems to be an old and widely known issue, but the only "solution" I found so far is "well, just don't use hubs and let the companion take it over", which obviously doesn't solve the case of pure-EHCI SoCs. (Well, another solutions applicable to those particular modems is to switch them to bulk mode, but it's slower.) Is this some limitation of the USB 2.0 spec or just a Linux issue? Any possible fixes or hackarounds? Regards, MP -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
