On Wed, Mar 26, 2014 at 11:01:54AM -0500, Dan Williams wrote: > On Tue, 2014-03-25 at 10:34 +0100, Alexander Stein wrote: > > As the module does not use the standard USB mechanism, the appropriate > > product and vendor IDs have to be added. > > Should these really be going into usb-serial-simple? If they are indeed > the PPP/Modem interface, then isn't something like 'option' a better > choice? Despite the name, it's the default WWAN serial driver. > > While the device probably has a net port that's usually used for data, > I'll be the PPP port can be used for data too, and that should be driven > by something that can achieve reasonable speeds. I'm not sure if it's > still the case, but the generic serial drivers didn't use to have great > buffer management and you could not get near HSDPA or EVDO-A speeds with > them. The generic usb-serial implementation was rewritten quite a while back now and these days uses two read and write urbs as well as a fifo to aggregate small writes (but that also implies an extra copy). The buffer sizes default to endpoint max-packet size but are also configurable. In all, speed shouldn't be a major issue anymore. Johan -- 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
