On Tuesday 10 Jan 2017 08:55:16 Vincent ABRIOU wrote: > On 01/09/2017 05:59 PM, Laurent Pinchart wrote: > > On Monday 09 Jan 2017 15:49:00 Vincent ABRIOU wrote: > >> On 01/09/2017 04:37 PM, Laurent Pinchart wrote: > >>> Hi Vincent, > >>> > >>> Thank you for the patch. > >>> > >>> On Monday 03 Oct 2016 13:27:16 Vincent Abriou wrote: > >>>> Allow uvcvideo compatible devices to allocate their output buffers > >>>> using contiguous DMA buffers. > >>> > >>> Why do you need this ? If it's for buffer sharing with a device that > >>> requires dma-contig, can't you allocate the buffers on the other device > >>> and import them on the UVC side ? > >> > >> Hi Laurent, > >> > >> I need this using Gstreamer simple pipeline to connect an usb webcam > >> (v4l2src) with a display (waylandsink) activating the zero copy path. > >> > >> The waylandsink plugin does not have any contiguous memory pool to > >> allocate contiguous buffer. So it is up to the upstream element, here > >> v4l2src, to provide such contiguous buffers. > > > > Isn't that a gstreamer issue ? > > It is not a gstreamer issue. It is the way it has been decided to work. > Waylandsink accept DMABUF contiguous buffer but it does not have its own > buffer pool. But why do you put the blame on the kernel when you decide to take the wrong decision in userspace ? :-) > >>>> Add the "allocators" module parameter option to let uvcvideo use the > >>>> dma-contig instead of vmalloc. > >>>> > >>>> Signed-off-by: Vincent Abriou <vincent.abriou@xxxxxx> > >>>> --- > >>>> > >>>> Documentation/media/v4l-drivers/uvcvideo.rst | 12 ++++++++++++ > >>>> drivers/media/usb/uvc/Kconfig | 2 ++ > >>>> drivers/media/usb/uvc/uvc_driver.c | 3 ++- > >>>> drivers/media/usb/uvc/uvc_queue.c | 23 ++++++++++++++++--- > >>>> drivers/media/usb/uvc/uvcvideo.h | 4 ++-- > >>>> 5 files changed, 38 insertions(+), 6 deletions(-) -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
