Dear All, How should a gadgetfs application cause an ACK to be sent to the host in response to a sucessfully received and processed control out transaction?
My first guess was to send a zero-byte write, but looking at the example gadgetfs program (http://www.linux-usb.org/gadget/usb.c), the only control out transactions that it handles are SET_CONFIGURATION and SET_INTERFACE, and it acks these with a zero-byte read: /* ... ack (a write would stall) */ status = read (fd, &status, 0); This does indeed work in these cases, but I have tried doing it for other control out transactions (i.e. type=vendor), where as far as I can see it doesn't work; the host never sees the ack and eventually times out. There's a good chance that I'm doing something stupid, but I'd like to understand whether I really should be doing reads or whether this is a special case for these particular control transactions. When I try doing a zero-byte write for the type=vendor transactions I get "Level 2 halted" (EL2HLT), which I suspect is the "write would stall" that the comment in usb.c is alluding to. Any suggestions anyone? Thanks, and Happy New Year. Phil. (You are welcome to CC me in any replies) ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
