Hi, Alan Stern <[email protected]> writes: > On Tue, 26 Sep 2017, Felipe Balbi wrote: > >> > Does uvc use isochronous transfers? I assume it would, since it's a >> > video protocol. >> >> yes, it does :-) >> >> > dummy-hcd does not support isochronous. I don't know what would happen >> >> really? Then why is it registering iso endpoints to the gadget layer? >> >> static const struct { >> const char *name; >> const struct usb_ep_caps caps; >> } ep_info[] = { >> #define EP_INFO(_name, _caps) \ >> { \ >> .name = _name, \ >> .caps = _caps, \ >> } >> >> /* everyone has ep0 */ >> EP_INFO(ep0name, >> USB_EP_CAPS(USB_EP_CAPS_TYPE_CONTROL, USB_EP_CAPS_DIR_ALL)), >> /* act like a pxa250: fifteen fixed function endpoints */ >> EP_INFO("ep1in-bulk", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)), >> EP_INFO("ep2out-bulk", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep3in-iso", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_IN)), >> EP_INFO("ep4out-iso", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep5in-int", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_IN)), >> EP_INFO("ep6in-bulk", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)), >> EP_INFO("ep7out-bulk", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep8in-iso", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_IN)), >> EP_INFO("ep9out-iso", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep10in-int", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_IN)), >> EP_INFO("ep11in-bulk", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)), >> EP_INFO("ep12out-bulk", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep13in-iso", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_IN)), >> EP_INFO("ep14out-iso", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep15in-int", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_IN)), >> /* or like sa1100: two fixed function endpoints */ >> EP_INFO("ep1out-bulk", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep2in-bulk", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)), >> /* and now some generic EPs so we have enough in multi config */ >> EP_INFO("ep3out", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep4in", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)), >> EP_INFO("ep5out", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep6out", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep7in", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)), >> EP_INFO("ep8out", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep9in", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)), >> EP_INFO("ep10out", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep11out", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep12in", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)), >> EP_INFO("ep13out", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), >> EP_INFO("ep14in", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)), >> EP_INFO("ep15out", >> USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), >> >> #undef EP_INFO >> }; >> >> > if you tried it, but one way or another it would not work the way you >> > want. >> >> if that's really the case, then maybe we should remove all the iso >> endpoints from dummy. Right? > > Or comment them out, in case somebody decides to add isochronous
Kinda pointless to leave commented out code, but fine.
> support in the future. Yes, there's no point having them in the
> driver, given the way it works currently. All isochronous URBs
> complete with a -ENOSYS error status:
>
> switch (usb_pipetype(urb->pipe)) {
> case PIPE_ISOCHRONOUS:
> /* FIXME is it urb->interval since the last xfer?
> * use urb->iso_frame_desc[i].
> * complete whether or not ep has requests queued.
> * report random errors, to debug drivers.
> */
> limit = max(limit, periodic_bytes(dum, ep));
> status = -ENOSYS;
> break;
>
> The comment could be improved too. I'll send in a patch.
Thank you :-)
--
balbi
signature.asc
Description: PGP signature
