Hi Simone, On Tuesday 03 February 2009, Simone Freddio wrote: > Hi Laurent, > > here the results of my tests: > > MaxPayloadTransferSize Value Returned from device > Result > 0 128 > uvcvideo: USB isochronous frame lost (-71). > 1 128 > uvcvideo: USB isochronous frame lost (-71). > 42 128 > uvcvideo: USB isochronous frame lost (-71). > 1024 1024 > works right with few USB iso frame lost > 0xFFFF 3072 > no error but also no capture :-( > > My conclusion is that MaxPayloadTransferSize, regardless of > specification, is not readonly... seems to be that device round this > value to the closest that is supported (see also my lsusb in file > lsusb.txt). > > I think that the right bandwidth allocation must be calculated in > the driver and set up in the device (the same you have done for > frameinterval value :-).
I'll see if I can compute an estimated maximum payload transfer size based on the information available to the driver, otherwise I will just just smaller allocations until one of them succeeds. I should get a Vimicro camera soon that I will use to develop and test the workaround. Best regards, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list Linux-uvc-devel@lists.berlios.de https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
