Hi, >-----Original Message----- >From: ext Drews, Paul [mailto:paul.dr...@intel.com] >Sent: Tuesday, January 18, 2011 1:17 AM >To: Kodihalli Deepak (Nokia-MS/Bangalore); Ohly, Patrick; >Kavuri Sateesh (Nokia-MS/Bangalore); amitc...@gmail.com; >Puranik Santosh (Nokia-MS/Bangalore); >kalle.aalto...@sasken.com; tuomas.kat...@ixonos.com; >mhuna...@gmail.com; juha.paalija...@ixonos.com; Duggirala >Karthik.2 (Nokia-MS/Helsinki) >Cc: meego-dev@meego.com >Subject: RE: Buteo MTP + gadgetfs
> >Here's what I'm worried about: > >Case A: MTP responder sends data over bulk pipe where the >length is known ahead of time. Data takes multiple packets >and is an exact multiple of packet length. MTP responder asks >for "fsync" on the last sendData() call. Since the length is >known ahead of time, a ZLP should _not_ be sent according to >the USB spec. Even though the initiator knows the length in advance, it expects a ZLP if the packet size is a multiple of the USB max packet length. We have seen this with both windows and linux (libmtp) initiators. >Case B: MTP responder sends data over bulk pipe but the >length is _not_ known ahead of time. Data takes multiple >packets and is an exact multiple of packet length. MTP >responder asks for "fsync" on the last sendData() call. >Since the length is _not_ known ahead of time, a ZLP _should_ >be sent according to the USB spec. AFAIK, this is not possible with MTP1 at least, i.e the length _is_ always known. Regards, Deepak _______________________________________________ MeeGo-dev mailing list MeeGo-dev@meego.com http://lists.meego.com/listinfo/meego-dev
