On Wed, Aug 19, 2020 at 01:16:51PM +0200, Tomasz Figa wrote: > Hi Christoph, > > On Wed, Aug 19, 2020 at 8:56 AM Christoph Hellwig <hch@xxxxxx> wrote: > > > > The V4L2-FLAG-MEMORY-NON-CONSISTENT flag is entirely unused, > > Could you explain what makes you think it's unused? It's a feature of > the UAPI generally supported by the videobuf2 framework and relied on > by Chromium OS to get any kind of reasonable performance when > accessing V4L2 buffers in the userspace. Because it doesn't do anything except on PARISC and non-coherent MIPS, so by definition it isn't used by any of these media drivers.