On Fri, Jun 27, 2014 at 09:15:25AM -0700, Steve Aarnio wrote: > On 06/11/2014 08:41 AM, Jesse Barnes wrote: > >On Wed, 11 Jun 2014 17:39:29 +0200 > >Daniel Vetter <daniel@xxxxxxxx> wrote: > > > >>On Wed, Jun 11, 2014 at 5:13 PM, Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> wrote: > >>>>- If you have a machine which uses tiled framebuffers and enables > >>>> swizzling in the BIOS your code will a) drop the swizzle setup in > >>>> gem_init_hw, breaking resume b) not set the swizzle settings correctly > >>>> in swizzle_detect, breaking swap in/out and pwrite/pread. Not sure such > >>>> a machine exists, but still. > >>> > >>>This would affect krh's MBA, which is why I wanted testing here... > >>>anyway I'll spin a new one and ask krh to test again. > >> > >>Hm, I've thought the issue with the MBA is that it used tiled fbs, but > >>non-swizzled. And then a mess ensued when we've enabled it. But yeah, > >>unfortunately with the new logic we need to retest :( > > > >Ah yeah I think you're right, either way, need more testing. > > > >Maybe we should have just gone with the first patch to never enable > >swizzling based on Art's assertion that it didn't matter. > > > > I hate to jump into the middle of a conversation that may or may not be > related to a patch I just posted... but... > > There was a very long internal discussion that the Windows guys had with > H/W. For Gen8+ H/W recommends disabling CSX swizzle. Technically, BDW still > supports it, but there is a bug _somewhere_ that makes it problematic. In > any case it goes away for sure with Gen9+, so disabling on Gen8 doesn't > hurt. > > According to the other discussion, the H/W guys say that enabling actually > hurts performance slightly, and the driver should leave the swizzle > decisions to the memory controller. Patch to disable swizzling detection on gen8+ in i915_gem_tiling.c (only there, imo ok to keep the hw paths around for setting up the registers) welcome ;-) -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
