On Thu, Aug 22, 2013 at 09:52:53PM +0300, Ville Syrjälä wrote: > On Thu, Aug 22, 2013 at 11:30:55AM -0700, Ben Widawsky wrote: > > On Thu, Aug 22, 2013 at 07:23:13PM +0300, ville.syrjala@xxxxxxxxxxxxxxx wrote: > > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > > > > All the different context sizes reported in the CXT_SIZE register > > > aren't meant to be simply added together. > > > > > > While BSpec is somewhat unclear on the topic of the actual context > > > size, empirical tests have now revealed the truth. So let's add a > > > big fat comment to remind people how it all works. > > > > By the way. I've done some digging. I believe (75% certain) pre-HSW, > > every context save writes the entire data. So if you wanted to set some > > pattern and see what HW actually overwrites, it should be doable. HSW+ > > though we can't do that. > > Ah right, so you were thinking of initializing the context w/ some > poison, and then see how much is left after the HW has saved. That I > didnb't actually do. Should be reasonable trivial though, so I guess > I'll try it. The same method could also be used to identify whether > HSW skips parts or rearranges the context dynamically. Yes, the only problem is it's not always trivial to invoke writes of some parts of the context (I fear). -- Ben Widawsky, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
