Messages in this thread | | | Subject | Re: [linux-usb-devel] Re: EHCI TT bandwidth (was Re: [PATCH] USB_BANDWIDTH documentation change) | From | Lee Revell <> | Date | Fri, 30 Dec 2005 14:16:38 -0500 |
| |
On Fri, 2005-12-30 at 14:13 -0500, Dan Streetman wrote: > On Thu, 29 Dec 2005, Lee Revell wrote: > > >How do I test them? Should this make USB audio work with > >CONFIG_USB_BANDWIDTH? > > It won't have any effect on CONFIG_USB_BANDWIDTH, as the EHCI transaction > translator scheudling code doesn't care about that config setting. This > also won't have any effect on USB 2.0 devices (e.g. a highspeed Audio > device). > > The updates will only help in the situation where there are multiple > lowpseed or fullspeed devices with periodic endpoints, all connected to > the same USB 2.0 (highspeed) hub. In that situation it's possible to > "fill up" the USB 2.0 hub's transaction translator periodic schedule with > only a few devices. The updates allow many more devices to fit in the > TT's periodic schedule. The specific number of devices depends on how > many periodic endpoints, those endpoint's poll rates, and their max packet > sizes. >
OK. For some reason I though that problem was fixed, I guess it was a different issue. ALSA users previously reported that a full speed audio device didn't work at all through a high speed hub at all but that it was fixed a few months ago.
Lee
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |