Holger Waechtler wrote:
Petr Nejedly wrote:The hardware is Asus WL500g - a mipsel/Broadcom BCM4710 based linux router/AP with USB port - the toy(hmmm... interesting geek setup -- what exactly do you try to achieve... DVB/IP Routing?;)
Multicast it at home + some scheduled DAB recording w/o running PC. (for DVB recording, single USB1.1 would probably be too slow)
About every webcam uses ISOC transfers and webcams are supported by that piece of HW,Now I don't know where to look for the problem further. Can the problem even be in the ttusb driver? Can there be some endianness problem in OHCI driver?
Isochronous transfers are not too common, only USB audio drivers use them as well. Have you tried a USB audio device, does this works on OHCI/MIPS?
As explained above, ISOC should generally work.
I don't know whether the OHCI driver in 2.4 supports isochronous transfers at all -- in the days when I started the ttusb code there have been some big TODOs left in the OHCI code. Maybe you want to check for open issues there or try a 2.6 kernel instead.
Where the data actually went (URBs were finished OK,
there probably was the transfer on the bus, ohci had to DMA the data somewhere, but I got no oops ;-)
Any ideas?
I would first try whether isochronous transfers are supported at all, then add some debug code in the OHCI driver. If the 2.4 code doesn't yet supports them it may or may not be easier to switch to 2.6 -- depends on how many drivers for your particular hardware need to get ported. As alternative you can also backport the 2.6 isochronous code to the 2.4 OHCI driver.
I'll try it as my time permits.
Have you asked on the linux-usb mailing list regarding the actual state of the OHCI driver?Not yet.