Hi,

Your kernel is ancient. You should either ask your kernel supplier
for support or switch to using a current upstream kernel if you want
help here.

I can just give some general libusb advice.

Pedro Erencia wrote:
> we are having a curious behaviour with the USB OTG throughput on a
> DM3730. Specifically, we get a much greater throughput with high cpu
> loads.
..
> A test program runs that retrieves data from the board with libusb
> bulk transfers.

Does the program use the async libusb API to ensure that multiple
transfers are submitted at any given time?

If not, and it is calling libusb_bulk_transfer() in a loop, then the
USB controller will be idle a lot, until Linux has scheduled the
libusb program, until the program has looped around and submitted
another transfer.

By submitting multiple transfers at once you ensure that the host
controller hardware will work independently of whatever else is going
on in the system. It's like with all DMA. You need to prepare buffers
ahead of time.


//Peter
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