Hi Laurent, > Hi Bhupesh, > > Thanks for the patch. > > On Thursday 28 March 2013 15:11:52 Bhupesh Sharma wrote: > > This patch reworks the videobuffer management logic present in the UVC > > webcam gadget and ports it to use the "more apt" videobuf2 framework > > for video buffer management. > > > > To support routing video data captured from a real V4L2 video capture > > device with a "zero copy" operation on videobuffers (as they pass from > > the V4L2 domain to UVC domain via a user-space application), we need > > to support USER_PTR IO method at the UVC gadget side. > > > > So the V4L2 capture device driver can still continue to use MMAP IO > > method and now the user-space application can just pass a pointer to > > the video buffers being dequeued from the V4L2 device side while > > queueing them at the UVC gadget end. This ensures that we have a "zero- > copy" > > design as the videobuffers pass from the V4L2 capture device to the > > UVC gadget. > > > > Note that there will still be a need to apply UVC specific payload > > headers on top of each UVC payload data, which will still require a > > copy operation to be performed in the 'encode' routines of the UVC > gadget. > > > > This patch also addresses one issue found out while porting the UVC > > gadget to videobuf2 framework: > > - In case the usb requests queued by the gadget get completed > > with a status of -ESHUTDOWN (disconnected from host), > > the queue of videobuf2 should be cancelled to ensure that the > > application space daemon is not left in a state waiting for > > a vb2 to be successfully absorbed at the USB side. > > > > Signed-off-by: Bhupesh Sharma <bhupesh.sharma@xxxxxx> > > Finally, > > Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > > :-) > Thanks for your time in reviewing this and previous patchsets :). If you can apply these 2 patches to your git tree (git://linuxtv.org/pinchartl/uvcvideo.git), I want to prepare and send out two more UVC patches: - One that supports UVC Bulk endpoint implementation. - Second that supports MEMCPY less implementation for adding UVC header to the UVC payload for UDC controllers which support SG implementation. In the meantime, probably we can request Felipe to pull UVC gadget related patches from your git repo. Regards, Bhupesh -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
