Mark Lord [mailto:mlord@xxxxxxxxx] > Sent: Friday, November 25, 2016 3:11 AM [...] > On 16-11-24 02:00 PM, Greg KH wrote: > > On Thu, Nov 24, 2016 at 01:34:08PM -0500, Mark Lord wrote: > >> One thought: bulk data streams are byte streams, not packets. > >> Scheduling on the USB bus can break up larger transfers across > >> multiple in-kernel buffers. A "real" URB buffer on USB2 is max 512 bytes. > >> The driver is providing 16384-byte buffers, and assumes that data will > >> never spill over from one such buffer to the next. > >> Yet the observations here consistently show otherwise. > > > > Wait, how do you know that data will not spill over? What is making > > that guarantee? Will the USB device send a "zero packet" in order to > > show that all of the "logical" data is now sent for this specific > > endpoint? Is there some sort of "framing" that the device does with the > > USB data so that the driver "knows" where the end of packet is? > > Exactly my point. > > > Check the zero-packet stuff for this device, that's tripped up many a > > USB driver writer over the years, myself included. > > I haven't tripped over it myself, but only because we were careful > to allow for such in the USB drivers I have worked on. > > The r8152 driver just assumes it never happens. What is the value of /sys/bus/usb/devices/.../power/control ? Could you make sure it is "on" and try again? Or you could call usb_disable_autosuspend() in probe(). Best Regards, Hayes ��.n��������+%������w��{.n�����{���)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
