On Fri, 14 Dec 2007, Jay Monkman wrote: > On Fri, Dec 14, 2007 at 11:03:59AM -0500, Alan Stern wrote: > > On Thu, 13 Dec 2007, Jay Monkman wrote: > > Does it also have a built-in OHCI controller? > > Thanks for your help. No, it only has the EHCI controller. I was > mistaken about the root hub - it has 2 ports, although only one is > connected to a transceiver. The manual for this CPU is at > http://www.freescale.com/files/32bit/doc/ref_manual/MPC8349ERM.pdf > > > > > Does the hub run at full speed or high speed? What about the audio > > device? > > The hub is a high speed hub, and the audio device is full speed. > > I have tried a full speed hub, and get a different failure. When I run > my test program, I get this from the kernel: > cannot submit datapipe for urb 0, error -28: not enough bandwidth > My test program shouldn't use all the bus bandwidth. It's full-duplex > stereo, 16 bits per sample at 32Khz. Even if the audio device is > really running at 48Khz, that's about 3 Mbps.
Yes, that's understandable. The problems surface whenever you have a full-speed device attached directly to the computer (rather than going through a high-speed hub). I don't know how the Freescale controller is supposed to work. Apparently it doesn't use a companion controller for full-speed connections. Maybe it has a Transaction Translator in its root hub instead. If that's the case, then the TT isn't working right. It could be a problem with the controller hardware or a problem with the driver; I have no idea which. Alan Stern - To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
