On Wed, 16 Mar 2016, ais523 wrote: > On Wed, 2016-03-16 at 10:07 -0400, Alan Stern wrote: > > On Wed, 16 Mar 2016, ais523 wrote: > > > One line summary of the problem: > > > Connecting an Osprey 2 Mini sometimes causes it to reset every > > 200ms > > > > Please post a usbmon trace showing what happens when you plug in the > > device. (See Documentation/usb/usbmon.txt for instructions). > > Here are two usbmon traces, one in which plugging in the device caused > a reset loop, one in which it didn't. In fact both logs show a loop of resets. I'll focus on just the first reset. > No reset loop: ... > ffff880118636a80 189630599 S Bo:1:006:1 -115 31 = 55534243 1f000000 02000000 80010a51 00000000 00000002 00000000 000000 > ffff880118636a80 189630639 C Bo:1:006:1 0 31 > > ffff88003f99ea80 189630649 S Bi:1:006:1 -115 2 < > ffff88003f99ea80 189635905 C Bi:1:006:1 -75 0 > ffff880118636a80 189635966 S Bi:1:006:1 -115 13 < > ffff880118636a80 189636263 C Bi:1:006:1 0 8 = 55534243 1f000000 > ffff88003f99ea80 189636339 S Co:1:002:0 s 23 03 0004 0002 0000 0 > ffff88003f99ea80 189636515 C Co:1:002:0 0 0 This shows a READ DISC INFORMATION command, asking the device to send 2 bytes (the first 2 bytes of the response indicate the total information length). The device tried to send back more than 2 bytes, violating the Mass Storage protocol. This led the computer to do a reset. After the reset (200 ms later) the computer tried sending the same command, and the same thing happened. That's where your loop comes from. There's no question about it -- your problem is caused by a buggy device. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
