On Mit, 2012-04-18 at 21:19 +1000, Benjamin Herrenschmidt wrote: > On Wed, 2012-04-18 at 12:44 +0200, Michel Dänzer wrote: > > On Mit, 2012-04-18 at 12:34 +0200, Michel Dänzer wrote: > > > On Mit, 2012-04-18 at 20:20 +1000, Benjamin Herrenschmidt wrote: > > > > > > > > I suspect there's a fundamental design issue with apple bridge in that > > > > the CPU to memory path isn't coherent at all with the GPU to memory path > > > > ie. even vs. cache flush instructions (ie buffers in the memory > > > > controllers can still be out of sync). > > > > > > > > Darwin does some gross hacks to work around that, some of them visible > > > > in the AGP drivers, some burried in the Apple driver, I don't know for > > > > sure. It's possible that they end up mapping all AGP memory as cache > > > > inhibited, but we can't do that because of our linear mapping. > > > > > > We are doing that though... > > > > This reminded me, I've been running with the patch below, but I'm not > > sure it makes any difference. Maybe Andreas or Jordan can try it. > > It certainly is something we need to do, provided we also know there > will be no subsequent access to that page via a cachable mapping until > it's removed from AGP.
TTM should take care of that. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Debian, X and DRI developer _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
