On Sun, Aug 20, 2023, Alan Stern wrote: > On Sat, Aug 19, 2023 at 12:06:53AM +0000, Thinh Nguyen wrote: > > On Fri, Aug 18, 2023, Alan Stern wrote: > > > Actually I agree with you. When a new SETUP packet arrives before the > > > old control transfer has finished, the UDC driver should cancel all > > > pending requests and then invoke the ->setup() callback. (I don't think > > > there is a standard error code for the cancelled requests; net2280 seems > > > to use -EPROTO whereas dummy-hcd seems to use -EOVERFLOW.) > > > > Those are very odd choice of error codes for cancelled request. Even > > though the gadget side doesn't have very defined error codes, I try to > > follow the equivalent doc from the host side > > (driver-api/usb/error-codes.rst), which is -ECONNRESET. > > > > Whenever I see -EPROTO, I associate that to a specific host error: > > transaction error. For -EOVERFLOW, I think of babble errors. > > Do you have a suggestion for an error code that all the UDCs should use > in this situation? -ECONNRESET is currently being used for requests > that were cancelled by usb_ep_dequeue(). Would -EREMOTEIO be more > suitable for requests attached to an aborted control transfer? > That works. It would be great if we can document the usb error codes for gadget side and keep them consistent across UDC drivers. I think there are only a few common errors: * Request aborted * Request dequeued * STALL * Data dropped (isoc only) Any other? Thanks, Thinh
