> > > > I'd like to fix this at some point, but I never got to understand wtf the > > blackbars were coming from, apart from it being something to do with > > evicted buffers. > > Aha! > > So, two characteristics of the black bars I remember: > > - They were 16-pixel (64-byte) horizontal stripes, 64-byte aligned. > That is, cache lines. > - They were black. > That is, the cache-line contents for a newly zeroed page > > Note also that the function to add pages to the page free lists - > drm_add_pages_locked() - calls set_memory_wc(), but it doesn't do the > other thing that drm_ttm_set_caching() does: call drm_clflush_pages()
Ah that could have been it. care to give it a hack, I'm on hols for another week or so. Dave. > > So, I believe the black bar problem was simply that when migrating a > buffer from vram to newly allocated system memory pages, cached data > written to those pages by the CPU wasn't flushed before blitting the > migrated data. > > If that theory makes sense, then 37136c81 is pretty much entirely > extraneous - it fixes the black bars by defeating the point of the free > list of uncached pages and doing the work of drm_ttm_set_caching() on > every page pulled out of the free list. > > - Owen > > > > ------------------------------------------------------------------------------ > Register Now for Creativity and Technology (CaT), June 3rd, NYC. CaT > is a gathering of tech-side developers & brand creativity professionals. Meet > the minds behind Google Creative Lab, Visual Complexity, Processing, & > iPhoneDevCamp asthey present alongside digital heavyweights like Barbarian > Group, R/GA, & Big Spaceship. http://www.creativitycat.com > _______________________________________________ > Mesa3d-dev mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/mesa3d-dev > > ------------------------------------------------------------------------------ Register Now for Creativity and Technology (CaT), June 3rd, NYC. CaT is a gathering of tech-side developers & brand creativity professionals. Meet the minds behind Google Creative Lab, Visual Complexity, Processing, & iPhoneDevCamp asthey present alongside digital heavyweights like Barbarian Group, R/GA, & Big Spaceship. http://www.creativitycat.com _______________________________________________ Mesa3d-dev mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
