On (20/01/22 11:18), Sergey Senozhatsky wrote: [..] > > > + * - > > > + - __u32 > > > - ``reserved``\ [1] > > > - A place holder for future extensions. Drivers and applications > > > - must set the array to zero. > > > + must set the array to zero, unless application wants to specify > > > + buffer management ``flags``. > > > > I think support for this flag should be signaled as a V4L2_BUF_CAP capability. > > If the capability is not set, then vb2 should set 'flags' to 0 to preserve the > > old 'Drivers and applications must set the array to zero' behavior. > > The patch set adds V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS towards the end of the > series, I guess I can shuffle the patches and change the wording here. Or I can add separate queue flag and V4L2_BUF_CAP: struct vb2_queue { ... allow_cache_hints:1 + allow_consistency_hints:1 ... } and then have CAP_SUPPORTS_CACHE_HINTS/CAP_SUPPORTS_CONSISTENCY_HINTS. -ss