2014-05-02 11:40 GMT-03:00 Walker Inman <win...@mit.edu>: > To further the below, I have now tested both on windows and linux with the > same result. It always takes until the 4th read call until my response > appears, even with the delay between reads set to zero. This seems like > read() is causing some state machine to progress..?? I will probably just > wrap the read call with a for loop that runs 4x -- but this seems like quite > a hack. > > Is there any documentation on how your logging module is configured? Id like > to know more about what is happening on my read calls. > > Also, is there any way to check if / how much data is waiting on a bulk in > ep without 'reading' the data? > > If the above 4x read calls are progressing a state machine, is there a way > to directly advance the state machine? > > Thanks --- fyi, im quite new to pyusb / lib usb but have written an embedded > usb cdc host so have some familiarity with usb etc. >
It feels like a hardware/firmware issues. A long time ago I worked with a multifunctional printer which used to enqueue empty packets to the USB controller. So, every command response had to be read twice: the first one was the empty packet, and then the packets with the real data. -- Best Regards, Wander Lairson Costa ------------------------------------------------------------------------------ Is your legacy SCM system holding you back? Join Perforce May 7 to find out: • 3 signs your SCM is hindering your productivity • Requirements for releasing software faster • Expert tips and advice for migrating your SCM now http://p.sf.net/sfu/perforce _______________________________________________ pyusb-users mailing list pyusb-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pyusb-users
