On Mon, Dec 09, 2019 at 03:13:13PM +0000, Chris Wilson wrote: > Quoting Ville Syrjala (2019-12-09 15:01:37) > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > > The modparam checks performed by sna_mode_wants_tear_free() don't > > generally work when the server is running as a regular user. Hence > > we can't rely on them to indicate whether FBC/PSR/etc is enabled. > > A lso the "Panel Self-Refresh" connector property doesn't actually > > exist so we can nuke that part as well. Let's just nuke the whole > > thing and assume we want dirtyfb always when tearfree is not enabled. > > > > I'll anyway want to enable FBC by default across the board soonish > > so the check wouldn't really buy us much (would just exclude i830 > > and a few old desktop chipsets which don't have FBC hardware). > > > > Additionally if we don't have working dirtyfb we really should > > enable tearfree by default because otherwise we're going to > > get horrible lag due to missing frontbuffer flushes. > > But we also want to enable TearFree anyway in most cases, and here we > are defaulting to off in cases where it was already on. > > I still don't know on what grounds the cut-off should be based, the > primary question is can we afford to keep an extra framebuffer plus any > gubbins memory? The worry about perf are now larger moot, so it boils > down to available memory -- in quite a few cases TearFree is a big > improvement on power management, but that I guess is currently snb+ > (although we can fix ilk render powerstandby). > > How about GTT > mappable aperture, based on the idea that we have room > to spare that can't be used for scanout? That would only disable gen2 by > default. Not sure. Ideally we should perhaps make it dynamic and enable tearfree only when the extra framebuffers won't hog too much of the gtt/physical RAM? But since it's not dynamic currently I guess that would involve some actual work. -- Ville Syrjälä Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
