On Tue, Dec 23, 2014 at 07:34:15AM +0100, Robert Baldyga wrote: > Hi Felipe, > > On 12/22/2014 05:34 PM, Felipe Balbi wrote: > > On Mon, Dec 15, 2014 at 11:05:22AM +0100, Robert Baldyga wrote: > >> On 12/15/2014 06:13 AM, Peter Chen wrote: > >>> On Fri, Dec 12, 2014 at 02:17:28PM +0100, Robert Baldyga wrote: > >>>> As usb function drivers assumes that all usb request will be completed > >>>> before function unbind call, we should supply such behavior. In some > >>>> cases ep_disable() won't kill all request effectively, because some > >>>> IN requests can be in running state. In such situation it's possible > >>>> to have unbind function called before last request completion, which > >>>> can cause problems. > >>> > >>> Doesn't the function's disable/unbind should call usb_ep_dequeue to make > >>> sure the transfer has ended? > >> > >> USB function drivers like ECM or HID surely doesn't. It looks like > >> there's assumption that all requests will be completed by UDC driver. > > > > that's a bug on those drivers :-) > > So we can't make assumptions that requests will be completed in > ep_disable()? oh, no you can. I misread it. > >> Function ep_disable() should complete requests in hardware driver, but > >> at least in DWC2 driver not all requests are completed at this stage > > > > and that's a bug on dwc2 :-) > > I have already found that out. Another UDC drivers simply kill all > request without waiting for currently running, so I did the same in > DWC2. Here is my patch: > http://www.spinics.net/lists/linux-usb/msg118698.html should be in my pull request already. > >> (request which are in hardware FIFO are omitted to give them chance to > >> be transferred). Those requests are forced to complete in udc_stop() > > > > that's wrong, we're disabling the endpoint anyway. Either dwc2 needs to > > wait_for_completion() or forcibly cancel the request. The bottom line is > > that control should not exit ep_disable() until all requests have been > > quiesced. > > So that's not bug in function drivers. They make correct assumption, > because they expect that requests will be completed in ep_disable(). right :-) -- balbi
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