Re: High speed, high bandwidth isoc
Alan Stern <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Mon, 16 Jul 2007, Steve Calfee wrote:
> I am working on a project using a generic (non-FPGA) cypress fx2 to
> test host controllers.
>
> The good news is that Linux runs interrupt IN/OUTs at 3x1024 byte
> packets uframe, 24MBytes per second, over as long as I have tested,
> seconds. Verified by a bus analyzer.
>
> The not so good news is that I have not been able to get high
> bandwidth isoc to work. I am using a stock Ubuntu Feisty - 2.6.20.15
> kernel. I am going through usbdevfs.
>
> On INs I get two 1024 packets per uframe, and on OUTs one 1024 packet
> per uFrame. It cannot be a device problem, because the host does not
> ask for more.
>
> So my questions are has this been tested? Is it a problem with my
> user mode program? Is my kernel too old? Should I keep looking for the cause?
The last person I know to work on this was Christopher ("Monty")
Montgomery <[email protected]>. See for example this email and the
following patches:
http://marc.info/?l=linux-usb-devel&m=115932798607111&w=2
His interest was specifically USB audio.
Alan Stern
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