> -----Original Message----- > From: Maarten Lankhorst [mailto:maarten.lankhorst@xxxxxxxxxxxxx] > Sent: Tuesday, May 28, 2013 12:23 AM > To: Inki Dae > Cc: 'Daniel Vetter'; 'Rob Clark'; 'linux-fbdev'; 'YoungJun Cho'; 'Kyungmin > Park'; 'myungjoo.ham'; 'DRI mailing list'; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; linux-media@xxxxxxxxxxxxxxx > Subject: Re: Introduce a new helper framework for buffer synchronization > > Hey, > > Op 27-05-13 12:38, Inki Dae schreef: > > Hi all, > > > > I have been removed previous branch and added new one with more cleanup. > > This time, the fence helper doesn't include user side interfaces and > cache > > operation relevant codes anymore because not only we are not sure that > > coupling those two things, synchronizing caches and buffer access > between > > CPU and CPU, CPU and DMA, and DMA and DMA with fences, in kernel side is > a > > good idea yet but also existing codes for user side have problems with > badly > > behaved or crashing userspace. So this could be more discussed later. > > > > The below is a new branch, > > > > https://git.kernel.org/cgit/linux/kernel/git/daeinki/drm- > exynos.git/?h=dma-f > > ence-helper > > > > And fence helper codes, > > > > https://git.kernel.org/cgit/linux/kernel/git/daeinki/drm- > exynos.git/commit/? > > h=dma-fence-helper&id=adcbc0fe7e285ce866e5816e5e21443dcce01005 > > > > And example codes for device driver, > > > > https://git.kernel.org/cgit/linux/kernel/git/daeinki/drm- > exynos.git/commit/? > > h=dma-fence-helper&id=d2ce7af23835789602a99d0ccef1f53cdd5caaae > > > > I think the time is not yet ripe for RFC posting: maybe existing dma > fence > > and reservation need more review and addition work. So I'd glad for > somebody > > giving other opinions and advices in advance before RFC posting. > > > NAK. > > For examples for how to handle locking properly, see Documentation/ww- > mutex-design.txt in my recent tree. > I could list what I believe is wrong with your implementation, but real > problem is that the approach you're taking is wrong. I just removed ticket stubs to show my approach you guys as simple as possible, and I just wanted to show that we could use buffer synchronization mechanism without ticket stubs. Question, WW-Mutexes could be used for all devices? I guess this has dependence on x86 gpu: gpu has VRAM and it means different memory domain. And could you tell my why shared fence should have only eight objects? I think we could need more than eight objects for read access. Anyway I think I don't surely understand yet so there might be my missing point. Thanks, Inki Dae > > ~Maarten _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
