On Fri, Jan 23, 2015 at 10:57:32PM -0800, Jeremiah Mahler wrote: > all, > > On Tue, Jan 20, 2015 at 06:48:42AM +0100, Daniel Vetter wrote: > > On Mon, Jan 19, 2015 at 08:40:24AM -0800, Matt Roper wrote: > > > On Mon, Jan 19, 2015 at 11:04:04AM +0000, Chris Wilson wrote: > > > > On Mon, Jan 19, 2015 at 11:51:43AM +0100, Daniel Vetter wrote: > > > > > There's also an issue in (most) X drivers which exaberates this > > > > > issues: When changing the cursor buffer the X cursor code does a a) > > > > > disable cursor b) update cursor image c) enable cursor cycle. > > > > > > > > Notably not -intel on which the bug has been observed. And more > > > > importantly, the slow downs don't seem to correlate with cursor change, > > > > just cursor movement. > > > > -Chris > > > > > > > > -- > > > > Chris Wilson, Intel Open Source Technology Centre > > > > > > It seems that the simple fix for this case (movement only) is to just > > > skip the prepare_fb/cleanup_fb calls (and the associated vblank wait) in > > > the transitional plane helper when newfb == oldfb. I just posted a > > > small patch that makes that change (and solves the cursor lag for me). > > > > > > This won't solve the case if userspace uses a different framebuffer for > > > each update (while trying to update faster than the refresh rate). Is > > > there any existing userspace that behaves this way that we can test > > > with? > > > > Hm, I've thought I've merged that patch already: > > > > commit ab58e3384b9f9863bfd029b458ff337d381bf6d2 > > Author: Daniel Vetter <daniel.vetter@xxxxxxxx> > > Date: Mon Nov 24 20:42:42 2014 +0100 > > > > drm/atomic-helper: Skip vblank waits for unchanged fbs > > > > Or is the problem here that the transitional plane helpers aren't up to > > the task? If so please reference that in your patch. > > > > And we still need a hack for the "changed fb cursor" issue, I'll whip > > something up. > > -Daniel > > -- > > Daniel Vetter > > Software Engineer, Intel Corporation > > +41 (0) 79 365 57 48 - http://blog.ffwll.ch > > Just checking if anyone has come up with a fix. I am still stuck at > next-20150112 because of this bug. I've merged a patch from Matt Roper: commit d99b70ce7d73d78a88311453ccdd0fa0a670dd50 Author: Matt Roper <matthew.d.roper@xxxxxxxxx> Date: Mon Jan 19 08:31:49 2015 -0800 drm/plane-helper: Skip prepare_fb/cleanup_fb when newfb==oldfb that should rectify the sluggish i915 cursor. But it's in a separate topic branch which isn't in linux-next. Should show up in drm-next next week though. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
