On 04.08.2016 18:51, Daniel Stone wrote: > On 4 August 2016 at 04:39, Michel Dänzer <michel@xxxxxxxxxxx> wrote: >> Patch 6 extends the ioctl with new flags, which allow userspace to >> explicitly specify the target vblank seqno. This can also avoid delaying >> flips in some cases where we are already in the target vertical blank >> period when the ioctl is called. > > Is there open userspace for this? Sure, referenced in patch 6: https://cgit.freedesktop.org/~daenzer/xf86-video-ati/commit/?id=fc884a8af25345c32bd4104c864ecfeb9bb3db9b https://cgit.freedesktop.org/~daenzer/xf86-video-amdgpu/commit/?id=b8631a9ba49c0d0ebe5dcd1dbfb68fcfe907296f > What's the behaviour vs. modeset: does the modeset request block until > the last-requested flip is complete? If so, is there some kind of upper > bound on the number of blank periods to wait for? Did you read the patch? :) The only change compared to the existing ioctl is that userspace can ask for a flip to take effect in the current vblank seqno. The code added by the patch checks for target vblank seqno > current vblank seqno + 1 and returns -EINVAL in that case. This is also documented in drm_mode.h. > Is all this tested somewhere? Yes, I've been using it for a while on all my machines. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
