On Mon, Oct 28, 2013 at 07:43:30PM +0200, Ville Syrjälä wrote: > On Mon, Oct 28, 2013 at 09:48:55AM -0700, Ben Widawsky wrote: > > On Mon, Oct 28, 2013 at 03:05:12PM +0200, Ville Syrjälä wrote: > > > On Mon, Oct 28, 2013 at 10:22:31AM -0200, Paulo Zanoni wrote: > > > > 2013/10/27 Daniel Vetter <daniel@xxxxxxxx>: > > > > > On Fri, Oct 25, 2013 at 03:27:50PM -0200, Paulo Zanoni wrote: > > > > >> 2013/10/24 Ben Widawsky <benjamin.widawsky@xxxxxxxxx>: > > > > >> > Production HSW does not need it. I confirmed this with Art. > > > > >> > > > > > >> > Signed-off-by: Ben Widawsky <ben@xxxxxxxxxxxx> > > > > >> > > > > >> I just hope these things don't start uncovering bugs :) > > > > >> > > > > >> Reviewed-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> > > > > > > > > > > Merged the first 2 patches of this series. Not sure what to do with the > > > > > other two, since fbc is essentially disabled on pre-hsw. And no one seems > > > > > to really work on it :( So I only see minimal reasons to frob with it ... > > > > > > > > IMHO what you said is another reason to actually merge the other two > > > > patches, since they make FBC-only WAs be applied only on FBC (e.g., > > > > probably never). > > > > > > Another reason would be keeping the codepaths at least somewhat similar. > > > Could make it a bit easier to fix things later. If it would be me who > > > gets to fix the FBC mess at some point, I'd try to fix it for all gens > > > for sure. > > > > > > At some point I posted a patch to attempt a quick FBC fix for SNB: > > > "[PATCH] drm/i915: Attempt to fix FBC render tracking with hardware contexts" > > > > > > In theory that could make FBC work equally well for SNB as it works for > > > IVB+. And I must confess that I have FBC enabled on my IVB ultrabook > > > currently since it appears to save a rather significant amount of power. > > > > > > -- > > > Ville Syrjälä > > > Intel OTC > > > > > > I just looked at your patch, and I should probably comment there, but > > it's 5 months old :D. Did you actually observe a fix of something with > > that patch? I feel like the way in which we enable/disable tracking, it > > shouldn't make a difference. > > I've never even tried to enable FBC on SNB ;) > > But it should easy to trick it into doing the wrong thing. > > 1) switch to context A > 2) page flip to buf 0 > -> FBC RT address will point to buf 0 > 3) switch to context B > 4) page flip to buf 1 > -> FBC RT address will point to buf 1 > 5) switch to context A > -> FBC RT addres will be restored to point to buf 0 > 6) render into buf 1 and observe that FBC doesn't invalidate > the compressed data > > -- > Ville Syrjälä > Intel OTC I thought this is fine because we set the enable bit concurrently with the base address, and disable when not being used. I really don't know the code well enough though. -- Ben Widawsky, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
