Hi, On Wed, Sep 24, 2014 at 02:18:14PM -0500, Felipe Balbi wrote: > On Wed, Sep 24, 2014 at 01:08:15PM -0500, Felipe Balbi wrote: > > On Wed, Sep 24, 2014 at 01:53:31PM -0400, Alan Stern wrote: > > > On Wed, 24 Sep 2014, Felipe Balbi wrote: > > > > > > > > I'll capture usbmon and send here shortly. > > > > > > > > here it is... Interesting part starts at line 73 (114 on this email) > > > > where the data transport received EPIPE (due to Stall). This time > > > > however, I was eventually able to talk to the device and managed to > > > > issue quite a few writes to it. > > > > > > Here's where the unexpected stuff begins: > > > > > > > ed2541c0 1237463240 S Bo:003:01 -115 31 = 55534243 06000000 c0000000 8000061a 003f00c0 00000000 00000000 000000 > > > > ed2541c0 1237463431 C Bo:003:01 0 31 > > > > > ec1a8540 1237463873 S Bi:003:01 -115 192 < > > > > ec1a8540 1237464053 C Bi:003:01 -32 0 > > > > ed2541c0 1237464158 S Co:003:00 s 02 01 0000 0081 0000 0 > > > > ed2541c0 1237464359 C Co:003:00 0 0 > > > > ed2541c0 1237468607 S Bi:003:01 -115 13 < > > > > ed2541c0 1237468802 C Bi:003:01 -75 0 > > > > > > This is the first MODE SENSE command. The gadget should send as much > > > data as it can before halting the bulk-IN endpoint. Instead, the > > > endpoint was halted first. > > > > > > Then, after the host cleared the halt, the gadget apparently sent the > > > data that _should_ have been sent previously. The host was expecting > > > to receive the CSW at this point, so there was an overflow error. > > > That's what caused the host to perform a reset. > > > > > > Evidently this UDC implements the set_halt method incorrectly. > > > According to the kerneldoc for usb_ep_set_halt: > > > > > > * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any > > > * transfer requests are still queued, or if the controller hardware > > > * (usually a FIFO) still holds bytes that the host hasn't collected. > > > > damn old bugs :-) I'll fix that up and Cc stable. > > alright fixed. Below you can see a combined diff which I'll still split > into patches so they can be applied properly. OTOH, there's really no way to split it. It's all needed to fix a single bug. Do you want me to add Reported-by: Alan Stern ? -- balbi
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