OK, meson has fix from Koen and Neil. I'll send the fix for sun4i. But rockchip and exynos need the help from Simon and Heiko because I don't have a device. Regards, Qiang On Wed, Nov 21, 2018 at 5:45 PM Daniel Vetter <daniel@xxxxxxxx> wrote: > > On Sun, Nov 18, 2018 at 08:44:57PM +0800, Qiang Yu wrote: > > add ".prepare_fb = drm_gem_fb_prepare_fb," in "drm_plane_helper_funcs" > > solve my flicker problem on Allwinner A64. > > Yeah, some drivers fail to set this. Would be great if you could submit > this bugfix. > > Thanks, Daniel > > > > > Thanks, > > Qiang > > On Sun, Nov 18, 2018 at 8:14 PM Qiang Yu <yuq825@xxxxxxxxx> wrote: > > > > > > I find the reservation object will be created when: dma_buf_export > > > if no reservation object created when buffer object creation. > > > > > > And the implicit fence can be synced before display in: drm_gem_fb_prepare_fb > > > but seems most display driver doesn't call this function. > > > > > > Regards, > > > Qiang > > > On Sun, Nov 18, 2018 at 10:43 AM Qiang Yu <yuq825@xxxxxxxxx> wrote: > > > > > > > > Hi Eric and Wladimir, > > > > > > > > GPU driver like VC4, Etnaviv and Lima only do rendering and left display > > > > to other DRM display drivers. So there should be a render/display sync > > > > problem for these drivers. > > > > > > > > As I know, there are two ways: implicit and explicit described here: > > > > https://www.collabora.com/news-and-blog/blog/2016/09/13/mainline-explicit-fencing-part-1/ > > > > > > > > The implicit way need the display DRM driver wait on the reservation object > > > > associated with that framebuffer before display it, the reservation > > > > object contains > > > > fence which is added by render DRM driver to indicate render finish: > > > > https://www.phoronix.com/scan.php?page=news_item&px=AMDGPU-Intel-4.9-PRIME-Ex-Patch > > > > > > > > I investigate a bit into these DRM display drivers using CMA GEM helpers, > > > > seems there's no reservation object at all, so it should be impossible to > > > > support implicit sync. > > > > > > > > Although explicit way is better, there are still some apps not support it like > > > > kodi-gbm. So how do VC4+PL111 and Etnaviv+IMX solve this sync problem, > > > > and do these drivers support implicit sync? > > > > > > > > Thanks, > > > > Qiang > > _______________________________________________ > > dri-devel mailing list > > dri-devel@xxxxxxxxxxxxxxxxxxxxx > > https://lists.freedesktop.org/mailman/listinfo/dri-devel > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
