> From: Alan Stern [mailto:st...@rowland.harvard.edu] > Sent: Thursday, September 25, 2014 11:08 AM > > On Thu, 25 Sep 2014, Paul Zimmerman wrote: > > > That's why I don't understand how this can happen for IN. AFAIK, a STALL > > is only sent in response to something the host sent in the CBW. At that > > point, there shouldn't be any IN transfers active. > > The gadget may send a partial response to the CBW. The end of the > response is marked with a STALL. The mass-storage gadget driver > submits the partial response and then calls usb_ep_set_halt() without > waiting for the IN data to be delivered. It relies on the UDC driver > returning -EAGAIN if any data is still pending.
I guess you're referring to the code under the DATA_DIR_TO_HOST case in finish_reply(). Felipe, in our vendor driver, the ep_set_halt() and ep_set_wedge() functions check the request queue for the endpoint, and if it is not empty, they return -EAGAIN. I see your patch for the dwc3 driver does add that, in addition to the FIFO empty check. Does it still work OK if you remove the FIFO empty check portion? -- Paul -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
